private function getKeyArgumentsString($charInfo, $combo)
    {
        $arguments = json_encode($charInfo);

        if (null !== $combo) {
            $arguments .= ', ' . json_encode($combo);
        }

        return $arguments;
    }
private function getKeyArgumentsString($charInfo, $combo)
    {
        $arguments = json_encode($charInfo);

        if (null !== $combo) {
            $arguments .= ', ' . json_encode($combo);
        }

        return $arguments;
    }
private function getKeyArgumentsString ( $ charInfo , $ combo ) { $ arguments = json_encode ( $ charInfo ) ; if ( null !== $ combo ) { $ arguments .= ', ' . json_encode ( $ combo ) ; } return $ arguments ; }
Return Key arguments string.

@param string $charInfo a char (eg. ‘b’) OR charCode (eg. 98) OR array(13,13) for pressing ENTER
@param string $combo    CTRL|ALT|SHIFT|META

@return string
Return Key arguments string .