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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 write(self, fptr):
 """Write a Component Mapping box to file. """

        length = 8 + 4 * len(self.component_index)
        write_buffer = struct.pack('>I4s', length, b'cmap')
        fptr.write(write_buffer)

        for j in range(len(self.component_index)):
            write_buffer = struct.pack('>HBB',
                                       self.component_index[j],
                                       self.mapping_type[j],
                                       self.palette_index[j])
            fptr.write(write_buffer)