 		}
 	}
 	
-	public static func enableContacts(between a: PhysicsBodyCategory, and b: PhysicsBodyCategory) {
+	public static func enableContact(between a: PhysicsBodyCategory, and b: PhysicsBodyCategory) {
 		combineSeperatedFlags(compositeA: a, compositeB: b) { (x, y) in
 			let previous = PhysicsBodyCategory.contacts[x] ?? Set<PhysicsBodyCategory>()
 			let updated = previous.union([y])

		}
	}
	
	private var seperatedFlags : [PhysicsBodyCategory] {
		return [PhysicsBodyCategory]()
	}
	
}


public extension PhysicsBodyCategory {
	
	public static func enableCollision(between a: PhysicsBodyCategory, and b: PhysicsBodyCategory) {
		combineSeperatedFlags(compositeA: a, compositeB: b) { (x, y) in
			let previous = PhysicsBodyCategory.collisions[x] ?? Set<PhysicsBodyCategory>()
