src/Http/ContentNegotiation/MediaTypeFormatters/MediaTypeFormatter.php
protected function encodingIsSupported(string $encoding): bool
    {
        $lowercaseSupportedEncodings = array_map('strtolower', $this->getSupportedEncodings());
        $lowercaseEncoding = strtolower($encoding);

        return in_array($lowercaseEncoding, $lowercaseSupportedEncodings, true);
    }
protected function encodingIsSupported(string $encoding): bool
    {
        $lowercaseSupportedEncodings = array_map('strtolower', $this->getSupportedEncodings());
        $lowercaseEncoding = strtolower($encoding);

        return in_array($lowercaseEncoding, $lowercaseSupportedEncodings, true);
    }
Checks whether or not an encoding is supported

@param string $encoding The encoding to check
@return bool True if the encoding is supported, otherwise false