code: def fetch_file(self, in_path, out_path):
          
          output = self.get_chain().call(
              ansible_mitogen.target.read_path,
              mitogen.utils.cast(in_path),
          )
          ansible_mitogen.target.write_path(out_path, output)
docs: Implement fetch_file() by calling the corresponding
          ansible_mitogen.target function in the target.
  
          :param str in_path:
              Remote filesystem path to read.
          :param str out_path:
              Local filesystem path to write.