Prepare a request for calling the execute command action.

def _ProcessCommandSource(self, source):
    """Prepare a request for calling the execute command action."""
    action = standard.ExecuteCommandFromClient
    request = rdf_client_action.ExecuteRequest(
        cmd=source.base_source.attributes["cmd"],
        args=source.base_source.attributes["args"],
    )
    yield action, request