docs: def create(self, project, email, role, **attrs):
          """
          Create a new :class:`Membership`.
  
          :param project: :class:`Project` id
          :param email: email of the :class:`Membership`
          :param role: role of the :class:`Membership`
          :param attrs: optional attributes of the :class:`Membership`
          """
          attrs.update({'project': project, 'email': email, 'role': role})
          return self._new_resource(payload=attrs)