code: def random(cls, span=1, seed=None):
          
          if seed is not None:
              random.seed(seed)
  
          def rand_vect(min, max):
              return (
                  random.uniform(min, max),
                  random.uniform(min, max),
                  random.uniform(min, max),
              )
  
          while True:
              try:
                  return cls(
                      origin=rand_vect(-span, span),
                      xDir=rand_vect(-1, 1),
                      normal=rand_vect(-1, 1),
                  )
              except RuntimeError:  # Base.FreeCADError inherits from RuntimeError
                  # Raised if xDir & normal vectors are parallel.
                  # (the chance is very low, but it could happen)
                  continue
docs: Creates a randomized coordinate system.
  
          Useful for confirming that an *assembly* does not rely on its
          origin coordinate system to remain intact.
  
          For example, the :class:`CoordSysIndicator` *assembly* aligns 3 boxes
          along each of the :math:`XYZ` axes.
          Positioning it randomly by setting its ``world_coords`` shows that each
          box is always positioned orthogonally to the other two.
  
          .. doctest::
  
              from cqparts_misc.basic.indicators import CoordSysIndicator
              from cqparts.display import display
              from cqparts.utils import CoordSystem
  
              cs = CoordSysIndicator()
              cs.world_coords = CoordSystem.random()
  
              display(cs)  # doctest: +SKIP
  
  
          :param span: origin of return will be :math:`\pm span` per axis
          :param seed: if supplied, return is psudorandom (repeatable)
          :type seed: hashable object
          :return: randomized coordinate system
          :rtype: :class:`CoordSystem`