Where is documentation for com.streamsets.pipeline.api?

The various code evaluators offer an option for “Record Type” of “Data Collector Records.” This is important as it avoids any unexpected type changes that occur otherwise.  However, I have been unable to find any documentation on the Api. Most of my success has been a result of good guessing starting from the three lines of example provided in the processor documentation. I have reached a point where guessing is not enough; where can I find the api documentation?