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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 _data(self):
 """A deep copy NDArray of the data array associated with the BaseSparseNDArray. This function blocks. Do not use it in performance critical code. """

        self.wait_to_read()
        hdl = NDArrayHandle()
        check_call(_LIB.MXNDArrayGetDataNDArray(self.handle, ctypes.byref(hdl)))
        return NDArray(hdl)