+ /**
+ * Resolves the command by its direct name and returns an instance of its class
+ *
+ * @param $namespace Namespace to look in
+ * @param $commandName The direct command name we shall resolve
+ * @return $commandInstance An instance of the command class
+ * @throws InvalidCommandException Thrown if $commandName is invalid
+ */
+ function resolveCommand (string $namespace, string $commandName);
+