issues: 314653502

This data as json

id node_id number title user state locked assignee milestone comments created_at updated_at closed_at author_association active_lock_reason draft pull_request body reactions performed_via_github_app state_reason repo type
314653502 MDU6SXNzdWUzMTQ2NTM1MDI= 2062 __contains__ does not work with DataArray 6815844 closed 0     2 2018-04-16T13:34:30Z 2018-04-16T15:51:30Z 2018-04-16T15:51:29Z MEMBER      

Code Sample, a copy-pastable example if possible

```python

da = xr.DataArray([0, 1, 2], dims='x') 0 in da ( warning omitted ) False 0 in da.values True ```

Problem description

__contains__ should work as np.ndarray does.

Expected Output

```python

0 in da True ```

 
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   completed 13221727 issue

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