code: def disjunct_hs_zero(cls, ops, kwargs):
      
      from qnet.algebra.core.hilbert_space_algebra import TrivialSpace
      from qnet.algebra.core.operator_algebra import ZeroOperator
      hilbert_spaces = []
      for op in ops:
          try:
              hs = op.space
          except AttributeError:  # scalars
              hs = TrivialSpace
          for hs_prev in hilbert_spaces:
              if not hs.isdisjoint(hs_prev):
                  return ops, kwargs
          hilbert_spaces.append(hs)
      return ZeroOperator
docs: Return ZeroOperator if all the operators in `ops` have a disjunct
      Hilbert space, or an unchanged `ops`, `kwargs` otherwise