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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 _create(self, monomer, mon_vector):
 """ create the polymer from the monomer Args: monomer (Molecule) mon_vector (numpy.array):
 molecule vector that starts from the start atom index to the end atom index """

        while self.length != (self.n_units-1):
            if self.linear_chain:
                move_direction = np.array(mon_vector) / np.linalg.norm(mon_vector)
            else:
                move_direction = self._next_move_direction()
            self._add_monomer(monomer.copy(), mon_vector, move_direction)