:calls: `PATCH /user/repository_invitations/:invitation_id <https://developer.github.com/v3/repos/invitations/>`
        :param invitation: :class:`github.Invitation.Invitation` or int
        :rtype: None

def accept_invitation(self, invitation):
        """
        :calls: `PATCH /user/repository_invitations/:invitation_id <https://developer.github.com/v3/repos/invitations/>`
        :param invitation: :class:`github.Invitation.Invitation` or int
        :rtype: None
        """
        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={}
        )