E11000
Also written: duplicate key error, code 11000, DuplicateKey
The error code the server gives when a write would break a unique index. In the Node driver it's a `MongoServerError` with `code` 11000.
Also written: duplicate key error, code 11000, DuplicateKey
The error code the server gives when a write would break a unique index. In the Node driver it's a `MongoServerError` with `code` 11000.