code: def _translate_src_oprnd(self, operand):
          
          if isinstance(operand, ReilRegisterOperand):
              return self._translate_src_register_oprnd(operand)
          elif isinstance(operand, ReilImmediateOperand):
              return smtsymbol.Constant(operand.size, operand.immediate)
          else:
              raise Exception("Invalid operand type")
docs: Translate source operand to a SMT expression.