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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 add_section(self, id_, parent_id, section_type, points):
        '''add a section

        Args:
            id_(int): identifying number of the section
            parent_id(int): identifying number of the parent of this section
            section_type(int): the section type as defined by POINT_TYPE
            points is an array of [X, Y, Z, R]
        '''
        # L.debug('Adding section %d, with parent %d, of type: %d with count: %d',
        #         id_, parent_id, section_type, len(points))
        assert id_ not in self.sections, 'id %s already exists in sections' % id_
        self.sections[id_] = BlockNeuronBuilder.BlockSection(parent_id, section_type, points)