`comp:` etc.  At this stage we check if the PR is valid and meets certain
  quality requirements. For example, we check if the CLA is signed, PR has
  sufficient description, if applicable unit tests are added, if it is a
  reasonable contribution (meaning it is not a single liner cosmetic PR).

**2. Valid?**

-   If the PR passes all the quality checks then we go ahead and assign a
    reviewer.

        API.

*   Tensors are no longer hashable, but instead compare element-wise with `==`
    and `!=`. Use `tf.compat.v1.disable_tensor_equality()` to return to the
    previous behavior.

*   Performing equality operations on Tensors or Variables with incompatible
    shapes an exception is no longer thrown. Instead `__eq__` returns False and
    `__ne__` returns True.