def get_repositories_by_ids(self, repository_ids=None):
if repository_ids is None:<EOL><INDENT>raise NullArgument()<EOL><DEDENT>repositories = []<EOL>for i in repository_ids:<EOL><INDENT>repository = None<EOL>url_path = construct_url('<STR_LIT>',<EOL>bank_id=i)<EOL>try:<EOL><INDENT>repository = self._get_request(url_path)<EOL><DEDENT>except (NotFound, OperationFailed):<EOL><INDENT>if self._repository_view == PLENARY:<EOL><INDENT>raise<EOL><DEDENT>else:<EOL><INDENT>pass<EOL><DEDENT><DEDENT>if repository:<EOL><INDENT>if not (self._repository_view == COMPARATIVE and<EOL>repository in repositories):<EOL><INDENT>repositories.append(repository)<EOL><DEDENT><DEDENT><DEDENT>return objects.RepositoryList(repositories)<EOL>
Gets a ``RepositoryList`` corresponding to the given ``IdList``.

        In plenary mode, the returned list contains all of the
        repositories specified in the ``Id`` list, in the order of the
        list, including duplicates, or an error results if an ``Id`` in
        the supplied list is not found or inaccessible. Otherwise,
        inaccessible ``Repositories`` may be omitted from the list and
        may present the elements in any order including returning a
        unique set.

        :param repository_ids: the list of ``Ids`` to retrieve
        :type repository_ids: ``osid.id.IdList``
        :return: the returned ``Repository list``
        :rtype: ``osid.repository.RepositoryList``
        :raise: ``NotFound`` -- an ``Id`` was not found
        :raise: ``NullArgument`` -- ``repository_ids`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

        *compliance: mandatory -- This method must be implemented.*