'Does this library exist in this modulestore. This method does not verify that the branch &/or
version in the library_id exists.
Returns the library_id of the course if it was found, else None.'

def has_library(self, library_id, ignore_case=False, **kwargs):

    if (not isinstance(library_id, LibraryLocator)):
        return None
    index = self.get_course_index(library_id, ignore_case)
    if index:
        return LibraryLocator(index['org'], index['course'], library_id.branch)
    return None
