static public function parse( $headerFieldString, $decodeQualifiedValues = FALSE ){
		if( !preg_match( '/^\S+:\s*.+$/', trim( $headerFieldString ) ) )
		 	throw new InvalidArgumentException( 'Given string is not an HTTP header' );
		list( $key, $value )	= preg_split( '/:/', trim( $headerFieldString ), 2 );
		$value	= trim( $value );
		if( $decodeQualifiedValues )
			$value	= self::decodeQualifiedValues( $value );
		return new Net_HTTP_Header_Field( trim( $key ), $value );
	}