code: def _rotate(coordinates, theta, around):
      
      around = np.asarray(around).reshape(3)
      if np.array_equal(around, np.zeros(3)):
          raise ValueError('Cannot rotate around a zero vector')
      return Rotation(theta, around).apply_to(coordinates)
docs: Rotate a set of coordinates around an arbitrary vector.
  
      Parameters
      ----------
      coordinates : np.ndarray, shape=(n,3), dtype=float
          The coordinates being rotated.
      theta : float
          The angle by which to rotate the coordinates, in radians.
      around : np.ndarray, shape=(3,), dtype=float
          The vector about which to rotate the coordinates.