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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 gmf_data_dt(self):
 """ Return a composite data type for the GMFs """

        return numpy.dtype(
            [('rlzi', U16), ('sid', U32),
             ('eid', U64), ('gmv', (F32, (len(self.imtls),)))])