_pickle : bool, optional
    Whether to allow writing pickled data. Default: True
pickle_kwargs : dict, optional
    Additional keyword arguments to pass to pickle.dump, excluding
    'protocol'. These are only useful when pickling objects in object
    arrays on Python 3 to Python 2 compatible format.

Raises
------
ValueError
    If the array cannot be persisted. This includes the case of
    allow_pickle=False and array being an object array.
Various other errors
    If the array contains Python objects as part of its dtype, the
    process of pickling them may raise various errors if the objects
    are not picklable.

r