why not return error when setting parents if there is a circle error

[nullne]

Several advices:

• SetParent, if you set 1 to a, then a == 1, but SetParent is more like AddParent
• If there are some potential circle errors, they should be thrown immediately rather than at runtime

[mikespook]

I would agree with the first point and it will be improved.

The second one, if we put circle detecting to the function it will reduce the performance significantly.

I suggest using InherCircle manually and adding it to each SetParent call if detecting circle errors is the key step to you.

Thank you!

[nullne]

By the way, thank you for your work