updateAttributes makes null all attributes which are not defined

[joneldiablo]

What type of issue are you creating?

• [X] Bug
• [ ] Enhancement
• [ ] Question

What version of this module are you using?

• [ ] 2.0.10 (Stable)
• [x] 2.1.0-rc.n (2.1 Release Candidate n)
• [ ] Other

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Please add a description for your issue:

I trying to use the method ....updateAttributes(id, data) the data object has many elements but not all of the table, then this method rewrite everything as null if not exist on data object