@classmethod
def map(cls, auth, resource, resource_mapping):
    """ Instantiate APIResource with Client authorization from resource name.
        :param dict auth: Client authorization.
        :param string resource: Resource name.
        :param dict resource_mapping: Resource mapping.
        :return: API Resource
        :rtype: ``APIResource``
        """
    if not resource in resource_mapping:
        return None
    return cls(auth=auth, children=resource_mapping[resource])
