The actual full request would look like:

ExecuteProcessRequest(
  args = ["compile blah"],
  digest = blah,
  nailgun_execute_process_request = ExecuteProcessRequest(
    argv = ["-XmX10G", "org.pantsbuild.Zinc"],
    digest = blurgle,
  ),
)

and the logic would only activate if

nailgun_execute_process_request

is non-empty