def is_timedelta64_ns_dtype(arr_or_dtype):
return _is_dtype(arr_or_dtype, lambda dtype: dtype == _TD_DTYPE)<EOL>
Check whether the provided array or dtype is of the timedelta64[ns] dtype.

This is a very specific dtype, so generic ones like `np.timedelta64`
will return False if passed into this function.

Parameters
----------
arr_or_dtype : array-like
    The array or dtype to check.

Returns
-------
boolean
    Whether or not the array or dtype is of the timedelta64[ns] dtype.

Examples
--------
>>> is_timedelta64_ns_dtype(np.dtype('m8[ns]'))
True
>>> is_timedelta64_ns_dtype(np.dtype('m8[ps]'))  # Wrong frequency
False
>>> is_timedelta64_ns_dtype(np.array([1, 2], dtype='m8[ns]'))
True
>>> is_timedelta64_ns_dtype(np.array([1, 2], dtype=np.timedelta64))
False