numpy.ndarray.__array__
method
- 
ndarray.__array__(|dtype) → reference if type unchanged, copy otherwise.
- 
Returns either a new reference to self if dtype is not given or a new array of provided data type if dtype is different from the current dtype of the array. 
    © 2005–2019 NumPy Developers
Licensed under the 3-clause BSD License.
    https://docs.scipy.org/doc/numpy-1.16.1/reference/generated/numpy.ndarray.__array__.html