parameters: (tn, fn)
return_statement: return fn, (fn + tn)
docstring: Calculate for.
docstring_summary: Calculate for.
docstring_tokens: Calculate for .
function: def _calculate_for(tn, fn):
      """Calculate for."""
      return fn, (fn + tn)
function_tokens: def _calculate_for ( tn , fn ) : return fn , ( fn + tn )