code: private PyExpr genPyExprUsingSoySyntax(OperatorNode opNode) {
      List<PyExpr> operandPyExprs = visitChildren(opNode);
      String newExpr = PyExprUtils.genExprWithNewToken(opNode.getOperator(), operandPyExprs, null);
  
      return new PyExpr(newExpr, PyExprUtils.pyPrecedenceForOperator(opNode.getOperator()));
    }
docs: Generates a Python expression for the given OperatorNode's subtree assuming that the Python
  expression for the operator uses the same syntax format as the Soy operator.
  
  @param opNode the OperatorNode whose subtree to generate a Python expression for
  @return the generated Python expression