parameters: (self, sc_expr_str_fn)
return_statement: return "\n\n".join(node.custom_str(sc_expr_str_fn) for node in self.nodes)
docstring: Works like Symbol.__str__(), but allows a custom format to be used for
          all symbol/choice references. See expr_str().
docstring_summary: Works like Symbol.__str__(), but allows a custom format to be used for
          all symbol/choice references. See expr_str().
docstring_tokens: Works like Symbol . __str__ () but allows a custom format to be used for all symbol / choice references . See expr_str () .
function: def custom_str(self, sc_expr_str_fn):
          """
          Works like Symbol.__str__(), but allows a custom format to be used for
          all symbol/choice references. See expr_str().
          """
          return "\n\n".join(node.custom_str(sc_expr_str_fn) for node in self.nodes)
function_tokens: def custom_str ( self , sc_expr_str_fn ) : return "\n\n" . join ( node . custom_str ( sc_expr_str_fn ) for node in self . nodes )