'Given a library key like "library-v1:ProblemX+PR0B", return the
\'library\' XBlock with meta-information about the library.
A specific version may be specified.
Returns None on error.'

def _get_library(self, library_key):

    if (not isinstance(library_key, LibraryLocator)):
        library_key = LibraryLocator.from_string(library_key)
    try:
        return self.store.get_library(library_key, remove_version=False, remove_branch=False, head_validation=False)
    except ItemNotFoundError:
        return None
