code: def insert_top(self, node):
      
      if not isinstance(node, grammar.STATEMENTS):
        raise ValueError
      self.to_insert_top.append(node)
docs: Insert statements at the top of the function body.
  
      Note that multiple calls to `insert_top` will result in the statements
      being prepended in that order; this is different behavior from `prepend`.
  
      Args:
        node: The statement to prepend.
  
      Raises:
        ValueError: If the given node is not a statement.