in src/objectEnumerationBuilder.ts [170:187]
public static selectorEquals(x: Selector, y: Selector): boolean {
// Normalize falsy to null
x = x || null;
y = y || null;
if (x === y)
return true;
if (!x !== !y)
return false;
if (x.id !== y.id)
return false;
if (x.metadata !== y.metadata)
return false;
return true;
}