Packages are imported one by one in alphabetical order during runtime.

The test doesn't identify package's order-dependent issues; for instance,
importing "tf.foo" followed by "tf.bar" won't reveal that "tf.bar" depends on
"tf.foo" being imported first.

The `_api/v2/api_packages.txt` file is generated during the TensorFlow API v2
init files creation process and is subsequently stored in the wheel file after

*   Improved support for NumPy style basic slicing including non-1 strides,
    ellipses, newaxis, and negative indices. For example complicated expressions
    like `foo[1, 2:4, tf.newaxis, ..., :-3:-1, :]` are now supported. In
    addition we have preliminary (non-broadcasting) support for sliced
    assignment to variables. In particular one can write
    `var[1:3].assign([1,11,111])`.