src/Robin/Ntlm/Encoding/MbstringEncodingConverter.php
public function convert($string, $to_encoding, $from_encoding = null)
    {
        $from_encoding = (null !== $from_encoding) ? $from_encoding : $this->resolveInputEncoding($string);

        $result = mb_convert_encoding($string, $to_encoding, $from_encoding);

        if (false === $result) {
            throw EncodingConversionFailureException::forStringAndEncodings($string, $from_encoding, $to_encoding);
        }

        return $result;
    }
public function convert($string, $to_encoding, $from_encoding = null)
    {
        $from_encoding = (null !== $from_encoding) ? $from_encoding : $this->resolveInputEncoding($string);

        $result = mb_convert_encoding($string, $to_encoding, $from_encoding);

        if (false === $result) {
            throw EncodingConversionFailureException::forStringAndEncodings($string, $from_encoding, $to_encoding);
        }

        return $result;
    }
{@inheritDoc}

A list of supported encodings can be determined by running
{@link http://php.net/manual/en/function.mb-list-encodings.php `mb_list_encodings()`}