protected function validateHeaderName($headerName) : void
	{
		if (! \is_string($headerName))
		{
			throw new \InvalidArgumentException('Header name must be a string');
		}
		else if (! \preg_match(HeaderInterface::RFC7230_TOKEN, $headerName))
		{
			throw new \InvalidArgumentException(\sprintf('The given header name "%s" is not valid', $headerName));
		}
	}
protected function validateHeaderName($headerName) : void
	{
		if (! \is_string($headerName))
		{
			throw new \InvalidArgumentException('Header name must be a string');
		}
		else if (! \preg_match(HeaderInterface::RFC7230_TOKEN, $headerName))
		{
			throw new \InvalidArgumentException(\sprintf('The given header name "%s" is not valid', $headerName));
		}
	}
protected function validateHeaderName ( $ headerName ) : void { if ( ! \ is_string ( $ headerName ) ) { throw new \ InvalidArgumentException ( 'Header name must be a string' ) ; } else if ( ! \ preg_match ( HeaderInterface :: RFC7230_TOKEN , $ headerName ) ) { throw new \ InvalidArgumentException ( \ sprintf ( 'The given header name "%s" is not valid' , $ headerName ) ) ; } }
Validates the given header name

@param mixed $headerName

@return void

@throws \InvalidArgumentException

@link https://tools.ietf.org/html/rfc7230#section-3.2
Validates the given header name