3 """Automated tests of the apt-p2p functionality.
5 This script runs several automatic tests of some of the functionality in
8 @type tests: C{dictionary}
9 @var tests: all of the tests that can be run.
10 The keys are the test names (strings) which are used on the command-line
11 to identify the tests (can not be 'all' or 'help'). The values are tuples
12 with four elements: a description of the test (C{string}), the bootstrap
13 nodes to start (C{dictionary}), the downloaders to start (C{dictionary},
14 and the apt-get commands to run (C{list}).
16 The bootstrap nodes keys are integers, which must be in the range 1-9.
17 The values are the dictionary of keyword options to pass to the function
18 that starts the bootstrap node (see L{start_bootstrap} below).
20 The downloaders keys are also integers in the range 1-99. The values are
21 the dictionary of keyword options to pass to the function
22 that starts the downloader node (see L{start_downloader} below).
24 The apt-get commands' list elements are tuples with 2 elements: the
25 downloader to run the command on, and the list of command-line
26 arguments to specify to the apt-get program.
29 @var CWD: the working directory the script was run from
30 @type apt_conf_template: C{string}
31 @var apt_conf_template: the template to use for the apt.conf file
35 from time import sleep, time
36 import sys, os, signal
37 from traceback import print_exc
38 from os.path import exists
40 tests = {'1': ('Start a single bootstrap and downloader, test updating and downloading ' +
45 (1, ['install', 'aboot-base']),
46 (1, ['install', 'aap-doc']),
47 (1, ['install', 'ada-reference-manual']),
48 (1, ['install', 'aspectj-doc']),
49 (1, ['install', 'fop-doc']),
50 (1, ['install', 'jswat-doc']),
51 (1, ['install', 'asis-doc']),
52 (1, ['install', 'bison-doc']),
53 (1, ['install', 'crash-whitepaper']),
56 '2': ('Start a single bootstrap and 2 downloaders to test downloading from a peer.',
62 (1, ['install', 'aboot-base']),
63 (2, ['install', 'aboot-base']),
64 (1, ['install', 'aap-doc']),
65 (1, ['install', 'ada-reference-manual']),
66 (1, ['install', 'fop-doc']),
67 (1, ['install', 'jswat-doc']),
68 (1, ['install', 'bison-doc']),
69 (1, ['install', 'crash-whitepaper']),
70 (2, ['install', 'aap-doc']),
71 (2, ['install', 'ada-reference-manual']),
72 (2, ['install', 'fop-doc']),
73 (2, ['install', 'jswat-doc']),
74 (2, ['install', 'bison-doc']),
75 (2, ['install', 'crash-whitepaper']),
78 '3': ('Start a single bootstrap and 6 downloaders, to test downloading' +
79 ' speeds from each other.',
88 (1, ['install', 'aboot-base']),
89 (1, ['install', 'ada-reference-manual']),
90 (1, ['install', 'fop-doc']),
91 (1, ['install', 'crash-whitepaper']),
93 (2, ['install', 'aboot-base']),
94 (2, ['install', 'ada-reference-manual']),
95 (2, ['install', 'fop-doc']),
96 (2, ['install', 'crash-whitepaper']),
98 (3, ['install', 'aboot-base']),
99 (3, ['install', 'ada-reference-manual']),
100 (3, ['install', 'fop-doc']),
101 (3, ['install', 'crash-whitepaper']),
103 (4, ['install', 'aboot-base']),
104 (4, ['install', 'ada-reference-manual']),
105 (4, ['install', 'fop-doc']),
106 (4, ['install', 'crash-whitepaper']),
108 (5, ['install', 'aboot-base']),
109 (5, ['install', 'ada-reference-manual']),
110 (5, ['install', 'fop-doc']),
111 (5, ['install', 'crash-whitepaper']),
113 (6, ['install', 'aboot-base']),
114 (6, ['install', 'ada-reference-manual']),
115 (6, ['install', 'fop-doc']),
116 (6, ['install', 'crash-whitepaper']),
119 '4': ('Start a single bootstrap and 1 downloader, requesting the same' +
120 ' packages multiple times to test caching.',
124 (1, ['install', 'aboot-base']),
125 (1, ['install', 'ada-reference-manual']),
126 (1, ['install', 'fop-doc']),
127 (1, ['install', 'crash-whitepaper']),
129 (1, ['install', 'aboot-base']),
130 (1, ['install', 'ada-reference-manual']),
131 (1, ['install', 'fop-doc']),
132 (1, ['install', 'crash-whitepaper']),
134 (1, ['install', 'aboot-base']),
135 (1, ['install', 'ada-reference-manual']),
136 (1, ['install', 'fop-doc']),
137 (1, ['install', 'crash-whitepaper']),
140 '5': ('Start a single bootstrap and 6 downloaders, update all to test' +
141 ' that they can all see each other.',
143 {1: ([], {'suites': 'contrib non-free'}),
144 2: ([], {'suites': 'contrib non-free'}),
145 3: ([], {'suites': 'contrib non-free'}),
146 4: ([], {'suites': 'contrib non-free'}),
147 5: ([], {'suites': 'contrib non-free'}),
148 6: ([], {'suites': 'contrib non-free'})},
157 '6': ('Test caching with multiple apt-get updates.',
166 '7': ('Test pipelining of multiple simultaneous downloads.',
170 (1, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
171 'aspectj-doc', 'fop-doc', 'asis-doc',
172 'bison-doc', 'crash-whitepaper',
173 'bash-doc', 'apt-howto-common', 'autotools-dev',
174 'aptitude-doc-en', 'asr-manpages',
175 'atomix-data', 'alcovebook-sgml-doc',
176 'afbackup-common', 'airstrike-common',
180 '8': ('Test pipelining of multiple simultaneous downloads with many peers.',
189 (1, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
190 'aspectj-doc', 'fop-doc', 'asis-doc',
191 'bison-doc', 'crash-whitepaper',
192 'bash-doc', 'apt-howto-common', 'autotools-dev',
193 'aptitude-doc-en', 'asr-manpages',
194 'atomix-data', 'alcovebook-sgml-doc',
195 'afbackup-common', 'airstrike-common',
198 (2, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
199 'aspectj-doc', 'fop-doc', 'asis-doc',
200 'bison-doc', 'crash-whitepaper',
201 'bash-doc', 'apt-howto-common', 'autotools-dev',
202 'aptitude-doc-en', 'asr-manpages',
203 'atomix-data', 'alcovebook-sgml-doc',
204 'afbackup-common', 'airstrike-common',
207 (3, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
208 'aspectj-doc', 'fop-doc', 'asis-doc',
209 'bison-doc', 'crash-whitepaper',
210 'bash-doc', 'apt-howto-common', 'autotools-dev',
211 'aptitude-doc-en', 'asr-manpages',
212 'atomix-data', 'alcovebook-sgml-doc',
213 'afbackup-common', 'airstrike-common',
216 (4, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
217 'aspectj-doc', 'fop-doc', 'asis-doc',
218 'bison-doc', 'crash-whitepaper',
219 'bash-doc', 'apt-howto-common', 'autotools-dev',
220 'aptitude-doc-en', 'asr-manpages',
221 'atomix-data', 'alcovebook-sgml-doc',
222 'afbackup-common', 'airstrike-common',
225 (5, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
226 'aspectj-doc', 'fop-doc', 'asis-doc',
227 'bison-doc', 'crash-whitepaper',
228 'bash-doc', 'apt-howto-common', 'autotools-dev',
229 'aptitude-doc-en', 'asr-manpages',
230 'atomix-data', 'alcovebook-sgml-doc',
231 'afbackup-common', 'airstrike-common',
234 (6, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
235 'aspectj-doc', 'fop-doc', 'asis-doc',
236 'bison-doc', 'crash-whitepaper',
237 'bash-doc', 'apt-howto-common', 'autotools-dev',
238 'aptitude-doc-en', 'asr-manpages',
239 'atomix-data', 'alcovebook-sgml-doc',
240 'afbackup-common', 'airstrike-common',
244 '9': ('Start a single bootstrap and 6 downloaders and test downloading' +
245 ' a very large file.',
254 (1, ['install', 'kde-icons-oxygen']),
256 (2, ['install', 'kde-icons-oxygen']),
258 (3, ['install', 'kde-icons-oxygen']),
260 (4, ['install', 'kde-icons-oxygen']),
262 (5, ['install', 'kde-icons-oxygen']),
264 (6, ['install', 'kde-icons-oxygen']),
269 assert 'all' not in tests
270 assert 'help' not in tests
273 apt_conf_template = """
275 // Location of the state dir
280 userstatus "status.user";
281 cdroms "cdroms.list";
284 // Location of the cache dir
285 Cache "var/cache/apt/" {
286 Archives "archives/";
287 srcpkgcache "srcpkgcache.bin";
288 pkgcache "pkgcache.bin";
293 SourceList "sources.list";
295 Preferences "preferences";
299 // Locations of binaries
301 methods "/usr/lib/apt/methods/";
304 dpkg "/usr/bin/dpkg --simulate";
305 dpkg-source "/usr/bin/dpkg-source";
306 dpkg-buildpackage "/usr/bin/dpkg-buildpackage";
307 apt-get "/usr/bin/apt-get";
308 apt-cache "/usr/bin/apt-cache";
312 /* Options you can set to see some debugging text They correspond to names
313 of classes in the source code */
316 pkgProblemResolver "false";
317 pkgDepCache::AutoInstall "false"; // what packages apt install to satify dependencies
319 pkgAcquire::Worker "false";
320 pkgAcquire::Auth "false";
322 pkgDPkgProgressReporting "false";
323 pkgOrderList "false";
326 pkgInitialize "false"; // This one will dump the configuration space
328 Acquire::Ftp "false"; // Show ftp command traffic
329 Acquire::Http "false"; // Show http command traffic
330 Acquire::gpgv "false"; // Show the gpgv traffic
331 aptcdrom "false"; // Show found package files
336 apt_p2p_conf_template = """
339 # Port to listen on for all requests (TCP and UDP)
342 # The rate to limit sending data to peers to, in KBytes/sec.
343 # Set this to 0 to not limit the upload bandwidth.
346 # The minimum number of peers before the mirror is not used.
347 # If there are fewer peers than this for a file, the mirror will also be
348 # used to speed up the download. Set to 0 to never use the mirror if
350 MIN_DOWNLOAD_PEERS = 3
352 # Directory to store the downloaded files in
353 CACHE_DIR = %(CACHE_DIR)s
355 # Other directories containing packages to share with others
356 # WARNING: all files in these directories will be hashed and available
357 # for everybody to download
360 # Whether it's OK to use an IP addres from a known local/private range
363 # Whether a remote peer can access the statistics page
366 # Unload the packages cache after an interval of inactivity this long.
367 # The packages cache uses a lot of memory, and only takes a few seconds
368 # to reload when a new request arrives.
369 UNLOAD_PACKAGES_CACHE = 5m
371 # Refresh the DHT keys after this much time has passed.
372 # This should be a time slightly less than the DHT's KEY_EXPIRE value.
375 # The user name to try and run as (leave blank to run as current user)
378 # Which DHT implementation to use.
379 # It must be possile to do "from <DHT>.DHT import DHT" to get a class that
380 # implements the IDHT interface.
381 DHT = apt_p2p_Khashmir
383 # Whether to only run the DHT (for providing only a bootstrap node)
384 DHT-ONLY = %(DHT-ONLY)s
387 # bootstrap nodes to contact to join the DHT
388 BOOTSTRAP = %(BOOTSTRAP)s
390 # whether this node is a bootstrap node
391 BOOTSTRAP_NODE = %(BOOTSTRAP_NODE)s
393 # checkpoint every this many seconds
394 CHECKPOINT_INTERVAL = 5m
396 # concurrent xmlrpc calls per find node/value request!
399 # how many hosts to post to
402 # How many values to attempt to retrieve from the DHT.
403 # Setting this to 0 will try and get all values (which could take a while if
404 # a lot of nodes have values). Setting it negative will try to get that
405 # number of results from only the closest STORE_REDUNDANCY nodes to the hash.
406 # The default is a large negative number so all values from the closest
407 # STORE_REDUNDANCY nodes will be retrieved.
408 RETRIEVE_VALUES = -10000
410 # how many times in a row a node can fail to respond before it's booted from the routing table
413 # never ping a node more often than this
414 MIN_PING_INTERVAL = 15m
416 # refresh buckets that haven't been touched in this long
417 BUCKET_STALENESS = 1h
419 # expire entries older than this
422 # whether to spew info about the requests/responses in the protocol
427 """Remove all the files and directories below a top-level one.
430 @param top: the top-level directory to start at
434 for root, dirs, files in os.walk(top, topdown=False):
436 os.remove(os.path.join(root, name))
438 os.rmdir(os.path.join(root, name))
441 """Join together a list of directories into a path string.
443 @type dir: C{list} of C{string}
444 @param dir: the path to join together
446 @return: the joined together path
452 joined = os.path.join(joined, i)
456 """Create all the directories to make a path.
458 @type dir: C{list} of C{string}
459 @param dir: the path to create
462 if not os.path.exists(join(dir)):
463 os.makedirs(join(dir))
466 """Create an empty file.
468 @type path: C{list} of C{string}
469 @param path: the path to create
473 f = open(join(path), 'w')
476 def start(cmd, args, work_dir = None):
477 """Fork and start a background process running.
480 @param cmd: the name of the command to run
481 @type args: C{list} of C{string}
482 @param args: the argument to pass to the command
483 @type work_dir: C{string}
484 @param work_dir: the directory to change to to execute the child process in
485 (optional, defaults to the current directory)
487 @return: the PID of the forked process
491 new_cmd = [cmd] + args
492 pid = os.spawnvp(os.P_NOWAIT, new_cmd[0], new_cmd)
496 """Stop a forked background process that is running.
499 @param pid: the PID of the process to stop
501 @return: the return status code from the child
505 # First try a keyboard interrupt
506 os.kill(pid, signal.SIGINT)
509 (r_pid, r_value) = os.waitpid(pid, os.WNOHANG)
513 # Try a keyboard interrupt again, just in case
514 os.kill(pid, signal.SIGINT)
517 (r_pid, r_value) = os.waitpid(pid, os.WNOHANG)
522 os.kill(pid, signal.SIGTERM)
525 (r_pid, r_value) = os.waitpid(pid, os.WNOHANG)
529 # Finally a kill, don't return until killed
530 os.kill(pid, signal.SIGKILL)
533 (r_pid, r_value) = os.waitpid(pid, os.WNOHANG)
537 def apt_get(num_down, cmd):
538 """Start an apt-get process in the background.
540 The default argument specified to the apt-get invocation are
541 'apt-get -d -q -c <conf_file>'. Any additional arguments (including
542 the apt-get action to use) should be specified.
544 @type num_down: C{int}
545 @param num_down: the number of the downloader to use
546 @type cmd: C{list} of C{string}
547 @param cmd: the arguments to pass to the apt-get process
549 @return: the PID of the background process
553 print '*************** apt-get (' + str(num_down) + ') ' + ' '.join(cmd) + ' ****************'
554 apt_conf = join([down_dir(num_down), 'etc', 'apt', 'apt.conf'])
555 dpkg_status = join([down_dir(num_down), 'var', 'lib', 'dpkg', 'status'])
556 args = ['-d', '-c', apt_conf, '-o', 'Dir::state::status='+dpkg_status] + cmd
557 pid = start('apt-get', args)
560 def bootstrap_address(num_boot):
561 """Determine the bootstrap address to use for a node.
563 @type num_boot: C{int}
564 @param num_boot: the number of the bootstrap node
566 @return: the bootstrap address to use
570 return 'localhost:1' + str(num_boot) + '969'
572 def down_dir(num_down):
573 """Determine the working directory to use for a downloader.
575 @type num_down: C{int}
576 @param num_down: the number of the downloader
578 @return: the downloader's directory
582 return os.path.join(CWD,'downloader' + str(num_down))
584 def boot_dir(num_boot):
585 """Determine the working directory to use for a bootstrap node.
587 @type num_boot: C{int}
588 @param num_boot: the number of the bootstrap node
590 @return: the bootstrap node's directory
594 return os.path.join(CWD,'bootstrap' + str(num_boot))
596 def start_downloader(bootstrap_addresses, num_down, options = {},
597 mirror = 'ftp.us.debian.org/debian',
598 suites = 'main contrib non-free', clean = True):
599 """Initialize a new downloader process.
601 The default arguments specified to the downloader invocation are
602 the configuration directory, apt port, minport, maxport and the
604 Any additional arguments needed should be specified by L{options}.
606 @type num_down: C{int}
607 @param num_down: the number of the downloader to use
608 @type options: C{dictionary}
609 @param options: the dictionary of string formatting values for creating
610 the apt-p2p configuration file (see L{apt_p2p_conf_template} above).
611 (optional, defaults to only using the default arguments)
612 @type mirror: C{string}
613 @param mirror: the Debian mirror to use
614 (optional, defaults to 'ftp.us.debian.org/debian')
615 @type suites: C{string}
616 @param suites: space separated list of suites to download
617 (optional, defaults to 'main contrib non-free')
618 @type clean: C{boolean}
619 @param clean: whether to remove any previous downloader files
620 (optional, defaults to removing them)
622 @return: the PID of the downloader process
626 assert num_down < 100
628 print '************************** Starting Downloader ' + str(num_down) + ' **************************'
630 downloader_dir = down_dir(num_down)
638 # Create the directory structure needed by apt
639 makedirs([downloader_dir, 'etc', 'apt', 'apt.conf.d'])
640 makedirs([downloader_dir, 'var', 'lib', 'apt', 'lists', 'partial'])
641 makedirs([downloader_dir, 'var', 'lib', 'dpkg'])
642 makedirs([downloader_dir, 'var', 'cache', 'apt', 'archives', 'partial'])
643 touch([downloader_dir, 'var', 'lib', 'apt', 'lists', 'lock'])
644 touch([downloader_dir, 'var', 'lib', 'dpkg', 'lock'])
645 touch([downloader_dir, 'var', 'lib', 'dpkg', 'status'])
646 touch([downloader_dir, 'var', 'cache', 'apt', 'archives', 'lock'])
648 # Create apt's config files
649 f = open(join([downloader_dir, 'etc', 'apt', 'sources.list']), 'w')
650 f.write('deb http://localhost:1%02d77/%s/ unstable %s\n' % (num_down, mirror, suites))
653 f = open(join([downloader_dir, 'etc', 'apt', 'apt.conf']), 'w')
654 f.write('Dir "' + downloader_dir + '"')
655 f.write(apt_conf_template)
658 defaults = {'PORT': '1%02d77' % num_down,
659 'CACHE_DIR': downloader_dir,
661 'BOOTSTRAP': bootstrap_addresses,
662 'BOOTSTRAP_NODE': 'no'}
665 defaults[k] = options[k]
666 f = open(join([downloader_dir, 'apt-p2p.conf']), 'w')
667 f.write(apt_p2p_conf_template % defaults)
670 pid = start('python', [join([sys.path[0], 'apt-p2p.py']),
671 '--config-file=' + join([downloader_dir, 'apt-p2p.conf']),
672 '--log-file=' + join([downloader_dir, 'apt-p2p.log']),],
676 def start_bootstrap(bootstrap_addresses, num_boot, options = [], clean = True):
677 """Initialize a new bootstrap node process.
679 The default arguments specified to the apt-p2p invocation are
680 the state file and port to use. Any additional arguments needed
681 should be specified by L{options}.
683 @type num_boot: C{int}
684 @param num_boot: the number of the bootstrap node to use
685 @type options: C{list} of C{string}
686 @param options: the arguments to pass to the bootstrap node
687 (optional, defaults to only using the default arguments)
688 @type clean: C{boolean}
689 @param clean: whether to remove any previous bootstrap node files
690 (optional, defaults to removing them)
692 @return: the PID of the downloader process
698 print '************************** Starting Bootstrap ' + str(num_boot) + ' **************************'
700 bootstrap_dir = boot_dir(num_boot)
708 makedirs([bootstrap_dir])
710 defaults = {'PORT': '1%d969' % num_boot,
711 'CACHE_DIR': bootstrap_dir,
713 'BOOTSTRAP': bootstrap_addresses,
714 'BOOTSTRAP_NODE': 'yes'}
717 defaults[k] = options[k]
718 f = open(join([bootstrap_dir, 'apt-p2p.conf']), 'w')
719 f.write(apt_p2p_conf_template % defaults)
722 pid = start('python', [join([sys.path[0], 'apt-p2p.py']),
723 '--config-file=' + join([bootstrap_dir, 'apt-p2p.conf']),
724 '--log-file=' + join([bootstrap_dir, 'apt-p2p.log']),],
729 def run_test(bootstraps, downloaders, apt_get_queue):
730 """Run a single test.
732 @type bootstraps: C{dictionary} of {C{int}: C{list} of C{string}}
733 @param bootstraps: the bootstrap nodes to start, keys are the bootstrap numbers and
734 values are the list of options to invoke the bootstrap node with
735 @type downloaders: C{dictionary} of {C{int}: (C{int}, C{list} of C{string})}
736 @param downloaders: the downloaders to start, keys are the downloader numbers and
737 values are the list of options to invoke the downloader with
738 @type apt_get_queue: C{list} of (C{int}, C{list} of C{string})
739 @param apt_get_queue: the apt-get downloader to use and commands to execute
740 @rtype: C{list} of (C{float}, C{int})
741 @return: the execution time and returned status code for each element of apt_get_queue
745 running_bootstraps = {}
746 running_downloaders = {}
751 boot_keys = bootstraps.keys()
753 bootstrap_addresses = bootstrap_address(boot_keys[0])
754 for i in xrange(1, len(boot_keys)):
755 bootstrap_addresses += '\n ' + bootstrap_address(boot_keys[i])
757 for k, v in bootstraps.items():
758 running_bootstraps[k] = start_bootstrap(bootstrap_addresses, k, **v)
762 for k, v in downloaders.items():
763 running_downloaders[k] = start_downloader(bootstrap_addresses, k, **v)
767 for (num_down, cmd) in apt_get_queue:
768 running_apt_get[num_down] = apt_get(num_down, cmd)
770 (pid, r_value) = os.waitpid(running_apt_get[num_down], 0)
771 elapsed = time() - start_time
772 del running_apt_get[num_down]
773 r_value = r_value / 256
774 apt_get_results.append((elapsed, r_value))
777 print '********** apt-get completed successfully in ' + str(elapsed) + ' sec. *****************'
779 print '********** apt-get finished with status ' + str(r_value) + ' in ' + str(elapsed) + ' sec. ************'
784 print '************************** Exception occurred **************************'
786 print '************************** will attempt to shut down *******************'
788 print '*********************** shutting down the apt-gets *******************'
789 for k, v in running_apt_get.items():
791 print 'apt-get', k, stop(v)
793 print '************************** Exception occurred **************************'
798 print '*********************** shutting down the downloaders *******************'
799 for k, v in running_downloaders.items():
801 print 'downloader', k, stop(v)
803 print '************************** Exception occurred **************************'
808 print '************************** shutting down the bootstraps *******************'
809 for k, v in running_bootstraps.items():
811 print 'bootstrap', k, stop(v)
813 print '************************** Exception occurred **************************'
816 print '************************** Test Results *******************'
818 for (num_down, cmd) in apt_get_queue:
820 s = str(num_down) + ': "apt-get ' + ' '.join(cmd) + '" '
821 if len(apt_get_results) > i:
822 (elapsed, r_value) = apt_get_results[i]
823 s += 'took ' + str(elapsed) + ' secs (' + str(r_value) + ')'
825 s += 'did not complete'
828 return apt_get_results
831 """Get the usage information to display to the user.
834 @return: the usage information to display
838 s = 'Usage: ' + sys.argv[0] + ' (all|<test>|help)\n\n'
839 s += ' all - run all the tests\n'
840 s += ' help - display this usage information\n'
841 s += ' <test> - run the <test> test (see list below for valid tests)\n\n'
846 s += 'test "' + str(k) + '" - ' + v[0] + '\n'
850 if __name__ == '__main__':
851 if len(sys.argv) != 2:
853 elif sys.argv[1] == 'all':
854 for k, v in tests.items():
855 run_test(v[1], v[2], v[3])
856 elif sys.argv[1] in tests:
857 v = tests[sys.argv[1]]
858 run_test(v[1], v[2], v[3])
859 elif sys.argv[1] == 'help':
862 print 'Unknown test to run:', sys.argv[1], '\n'