code: def complex_raise_stmt_handle(self, tokens):
          
          internal_assert(len(tokens) == 2, "invalid raise from tokens", tokens)
          if self.target.startswith("3"):
              return "raise " + tokens[0] + " from " + tokens[1]
          else:
              return (
                  raise_from_var + " = " + tokens[0] + "\n"
                  + raise_from_var + ".__cause__ = " + tokens[1] + "\n"
                  + "raise " + raise_from_var
              )
docs: Process Python 3 raise from statement.