def _get_plugin_specs_as_list(specs):
if specs is not None and not isinstance(specs, types.ModuleType):<EOL><INDENT>if isinstance(specs, six.string_types):<EOL><INDENT>specs = specs.split("<STR_LIT:U+002C>") if specs else []<EOL><DEDENT>if not isinstance(specs, (list, tuple)):<EOL><INDENT>raise UsageError(<EOL>"<STR_LIT>"<EOL>"<STR_LIT>" % specs<EOL>)<EOL><DEDENT>return list(specs)<EOL><DEDENT>return []<EOL>
Parses a list of "plugin specs" and returns a list of plugin names.

Plugin specs can be given as a list of strings separated by "," or already as a list/tuple in
which case it is returned as a list. Specs can also be `None` in which case an
empty list is returned.