code: def construct_include(self, node):
          
  
          filename = os.path.join(self._root, self.construct_scalar(node))
          filename = os.path.abspath(filename)
          extension = os.path.splitext(filename)[1].lstrip('.')
  
          with open(filename, 'r') as f:
              if extension in ('yaml', 'yml'):
                  return yaml.load(f, Loader=self)
              else:
                  return ''.join(f.readlines())
docs: Include file referenced at node.