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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def astype(self, dtype, copy=True):
 """ Cast to a NumPy array or IntegerArray with 'dtype'. Parameters dtype : str or dtype Typecode or data-type to which the array is cast. copy : bool, default True Whether to copy the data, even if not necessary. If False, a copy is made only if the old dtype does not match the new dtype. Returns ------- array : ndarray or IntegerArray NumPy ndarray or IntergerArray with 'dtype' for its dtype. Raises ------ TypeError if incompatible type with an IntegerDtype, equivalent of same_kind casting """


        # if we are astyping to an existing IntegerDtype we can fastpath
        if isinstance(dtype, _IntegerDtype):
            result = self._data.astype(dtype.numpy_dtype, copy=False)
            return type(self)(result, mask=self._mask, copy=False)

        # coerce
        data = self._coerce_to_ndarray()
        return astype_nansafe(data, dtype, copy=None)