function Relay$1(params) {
    Transform.call(this, null, params);
  }
Relays a data stream between data processing pipelines.
If the derive parameter is set, this transform will create derived
copies of observed tuples. This provides derived data streams in which
modifications to the tuples do not pollute an upstream data source.
@param {object} params - The parameters for this operator.
@param {number} [params.derive=false] - Boolean flag indicating if
  the transform should make derived copies of incoming tuples.
@constructor