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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 _maybe_cast_to_float64(da):
 """Cast DataArrays to np.float64 if they are of type np.float32. Parameters da : xr.DataArray Input DataArray Returns ------- DataArray """

    if da.dtype == np.float32:
        logging.warning('Datapoints were stored using the np.float32 datatype.'
                        'For accurate reduction operations using bottleneck, '
                        'datapoints are being cast to the np.float64 datatype.'
                        ' For more information see: https://github.com/pydata/'
                        'xarray/issues/1346')
        return da.astype(np.float64)
    else:
        return da