Java function interop is a set of utility functions originally from Lightbend's Akka ASL2 version used when interopting between Java and Scala.
The datatypes within Java Function Interopt are based off the latest Akka ASL2 codebase (see https://github.com/akka/akka/tree/6680c47dcc2305906a44d7794081682211d7ee0b). The original authors of these datatypes within Akka can be seen here.