def __contains__(self, package):
return (package.resource._repository.uid in self._repository_uids)<EOL>
See if a package is in this list of repositories.

        Note:
            This does not verify the existance of the resource, only that the
            resource's repository is in this list.

        Args:
            package (`Package` or `Variant`): Package to search for.

        Returns:
            bool: True if the resource is in the list of repositories, False
            otherwise.