azure-storage-common/src/Common/Internal/Utilities.php
public static function appendDelimiter($string, $delimiter)
    {
        if (!self::endsWith($string, $delimiter)) {
            $string .= $delimiter;
        }

        return $string;
    }
public static function appendDelimiter($string, $delimiter)
    {
        if (!self::endsWith($string, $delimiter)) {
            $string .= $delimiter;
        }

        return $string;
    }
Append the delimiter to the string. The delimiter will not be added if
the string already ends with this delimiter.

@param string $string    The string to add delimiter to.
@param string $delimiter The delimiter to be added.

@return string