code: def to_hubo(self):
          
          if self.vartype is Vartype.SPIN:
              return self.to_binary().to_hubo()
  
          H = {tuple(term): bias for term, bias in self.items() if term}
          offset = self[tuple()] if tuple() in self else 0
          return H, offset
docs: Construct a higher-order unconstrained binary optimization (HUBO)
          problem from a binary polynomial.
  
          Returns:
              tuple: A 2-tuple of the form (`H`, `offset`) where `H` is the HUBO
              and `offset` is the linear offset.