+ /**
+ * Sets a default value in the config cache. Ignores already existing keys.
+ *
+ * @param string $cat Config category
+ * @param string $k Config key
+ * @param mixed $v Default value to set
+ */
+ private function setDefaultConfigValue($cat, $k, $v)
+ {
+ if (!isset($this->config[$cat][$k])) {
+ $this->setConfigValue($cat, $k, $v);
+ }
+ }
+