FilterFunc returns a unary function (api.UnFunc) which applies the user-defined filtering to apply predicates that filters out data items from being included in the downstream.

FlatMapFunc returns an unary function which applies a user-defined function which takes incoming comsite items and deconstruct them into individual items which can then be re-streamed.

MapFunc returns an unary function which applies the user-defined function which maps, one-to-one, the incomfing value to a new value.

NewUnary creates *UnaryOperator value.

ProcessFunc returns a unary function which applies the specified user-defined function that processes data items from upstream and returns a result value.

UnaryOp is an executor node that can execute a unary operation (i.e.