how to use a static method as a stream Function

Hi all,

Is there any way to use something akin to the double colon notation,
to use a static method as a Function in a collection stream?

Otherwise, if I have to instantiate it as a jython class that then
delegates to the static method, performance suffers greatly.

For example, how can one use java.lang.Float's sum method, which takes
two floating-point numbers as arguments, in a reduce operation?

Thank you.

Best wishes,

Albert