sequelize/sequelize — pull request #1374 by tonytamps (2014-02-10 23:45:19+00:00)
Title: Allows a user to define and validate an immutable field

This came about because of an issue we had where an auto-increment primary key was able to be changed.

To prevent this I created a sort of 'set once' field.

Since your old version of validator doesn't allow extending, I had to place the definition inline.

Let me know if you have any questions or concerns. :smile:

Tony T