src/StringType.php
public static function isEncodingSupported($encoding)
    {
        $encoding = strtolower($encoding);

        if (isset (static::supportedEncodings()[$encoding])) {
            return true;
        }

        return false;
    }
public static function isEncodingSupported($encoding)
    {
        $encoding = strtolower($encoding);

        if (isset (static::supportedEncodings()[$encoding])) {
            return true;
        }

        return false;
    }
Is this encoding supported?

@param  string  $encoding
@return bool