private static function _encodeQuotedPrintable($str)
    {
        $str = str_replace('=', '=3D', $str);
        $str = str_replace(self::$qpKeys, self::$qpReplaceValues, $str);
        $str = rtrim($str);
        return $str;
    }
private static function _encodeQuotedPrintable($str)
    {
        $str = str_replace('=', '=3D', $str);
        $str = str_replace(self::$qpKeys, self::$qpReplaceValues, $str);
        $str = rtrim($str);
        return $str;
    }
private static function _encodeQuotedPrintable ( $ str ) { $ str = str_replace ( '=' , '=3D' , $ str ) ; $ str = str_replace ( self :: $ qpKeys , self :: $ qpReplaceValues , $ str ) ; $ str = rtrim ( $ str ) ; return $ str ; }
Converts a string into quoted printable format.

@param  string $str
@return string
Converts a string into quoted printable format .