code: def get_transformation(self, coordinates):
          
          atom1, atom2 = self.hinge_atoms
          center = coordinates[atom1]
          axis = coordinates[atom1] - coordinates[atom2]
          axis /= np.linalg.norm(axis)
          angle = np.random.uniform(-self.max_amplitude, self.max_amplitude)
          return Complete.about_axis(center, angle, axis)
docs: Construct a transformation object