human
Solve the following python programming problem given the following code:
# Define a trivial preprocessor
class PreZeros(Preprocessors):
    def __init__(self, map_magnetogram):
        super(PreZeros, self).__init__(map_magnetogram)

    def _preprocessor(self):
        # Adding in custom parameters to the meta
        self.meta['preprocessor_routine'] = 'Zeros Preprocessor'

        # Creating the trivial zeros map of the same shape as the input map
        map_output = sunpy.map.Map((np.zeros(self.map_input.data.shape),
                                    self.meta))

        # Outputting the map.
        return map_output

# Generate the boundary
aMap2D = sunpy.map.Map(
    'C://git//solarextrapolation//solarextrapolation//data//example_data_(100x100)__01_hmi.fits')
aPrePro = PreZeros(aMap2D.submap([0, 10], [0, 10]))
aPreProData = aPrePro.preprocess()

# aPreProData = aMap2D.submap([0,10], [0,10])

# Some checks:
#aPreProData.data # Should be a 2D zeros array.
#aPreProData.meta
#aPreProData.meta['preprocessor_routine']
#aPreProData.meta['preprocessor_start_time']
Given the above code, generate some markdown instructions for it.
assistant
#Here is the Python program you requested.

Defining a Custom Preprocessor and Extrapolator
Here you will be creating trivial preprocessor and and exztrqapolatoirs
following the API.
Testing a preprocessor