human
Solve the following python programming problem given the following code:
# Define trivial extrapolator
class ExtZeros(Extrapolators):
    def __init__(self, map_magnetogram, **kwargs):
        super(ExtZeros, self).__init__(map_magnetogram, **kwargs)

    def _extrapolation(self):
        # Adding in custom parameters to the meta
        self.meta['extrapolator_routine'] = 'Zeros Extrapolator'

        arr_4d = np.zeros([self.map_boundary_data.data.shape[0],
                           self.map_boundary_data.data.shape[0], self.z, 3])
        return Map3D((arr_4d, self.meta))

aExt = ExtZeros(
    aPreProData,
    filepath='C://Users/Alex/solarextrapolation/solarextrapolation/3Dmap.m3d')
aMap3D = aExt.extrapolate()

# Some checks:
#aMap3D.data # Should be a 4D zeros array.
#aMap3D.meta
#aMap3D.meta['extrapolator_routine']
#aMap3D.meta['extrapolator_start_time']

# Testing a Map3DCube

aMapCube = Map3DCube(aMap3D, aMap3D)
aMapCube[0]
aMapCube[0].data
aMapCube[0].meta
aMapCube[1].data
aMapCube[1].meta
"""
Given the above code, generate some markdown instructions for it.
assistant
#Here is the Python program you requested.

Testing an extrapolator