intersectConnectionStates = (a, b) => {
	if (a === false || b === false) return false;
	if (a === true) return b;
	if (b === true) return a;
	if (a === CIRCULAR_CONNECTION) return b;
	if (b === CIRCULAR_CONNECTION) return a;
	return a;
}
@param {ConnectionState} a first
@param {ConnectionState} b second
@returns {ConnectionState} intersected