code: def transform(self, maps):
          
          a, az, po = self._inputs
          data = coordinates.spherical_to_cartesian(maps[a], maps[az], maps[po])
          out = {param : val for param, val in zip(self._outputs, data)}
          return self.format_output(maps, out)
docs: This function transforms from spherical to cartesian spins.
  
          Parameters
          ----------
          maps : a mapping object
  
          Examples
          --------
          Convert a dict of numpy.array:
  
          >>> import numpy
          >>> from pycbc import transforms
          >>> t = transforms.SphericalSpin1ToCartesianSpin1()
          >>> t.transform({'spin1_a': numpy.array([0.1]), 'spin1_azimuthal': numpy.array([0.1]), 'spin1_polar': numpy.array([0.1])})
              {'spin1_a': array([ 0.1]), 'spin1_azimuthal': array([ 0.1]), 'spin1_polar': array([ 0.1]),
               'spin2x': array([ 0.00993347]), 'spin2y': array([ 0.00099667]), 'spin2z': array([ 0.09950042])}
  
          Returns
          -------
          out : dict
              A dict with key as parameter name and value as numpy.array or float
              of transformed values.