def has_in_collaborators(self, collaborator):
assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, unicode)), collaborator<EOL>if isinstance(collaborator, github.NamedUser.NamedUser):<EOL><INDENT>collaborator = collaborator._identity<EOL><DEDENT>status, headers, data = self._requester.requestJson(<EOL>"<STR_LIT:GET>",<EOL>self.url + "<STR_LIT>" + collaborator<EOL>)<EOL>return status == <NUM_LIT><EOL>
:calls: `GET /repos/:owner/:repo/collaborators/:user <http://developer.github.com/v3/repos/collaborators>`_
:param collaborator: string or :class:`github.NamedUser.NamedUser`
:rtype: bool