code: def accept_invitation(self, invitation):
          
          assert isinstance(invitation, github.Invitation.Invitation) or isinstance(invitation, int)
  
          if isinstance(invitation, github.Invitation.Invitation):
              invitation = invitation.id
  
          headers, data = self._requester.requestJsonAndCheck(
              "PATCH",
              "/user/repository_invitations/" + str(invitation),
              input={}
          )
docs: :calls: `PATCH /user/repository_invitations/:invitation_id <https://developer.github.com/v3/repos/invitations/>`
          :param invitation: :class:`github.Invitation.Invitation` or int
          :rtype: None