code: public static boolean isPolyExpression(Expression expression) {
          if (expression instanceof EnclosedExpr) {
              throw new UnsupportedOperationException(expression.toString());
          }
          if (expression instanceof ObjectCreationExpr) {
              // A class instance creation expression is a poly expression (§15.2) if it uses the diamond form for type
              // arguments to the class, and it appears in an assignment context or an invocation context (§5.2, §5.3).
              // Otherwise, it is a standalone expression.
              ObjectCreationExpr objectCreationExpr = (ObjectCreationExpr)expression;
              if (objectCreationExpr.isUsingDiamondOperator()) {
                  throw new UnsupportedOperationException(expression.toString());
              } else {
                  return false;
              }
          }
          if (expression instanceof MethodCallExpr) {
              MethodCallExpr methodCallExpr = (MethodCallExpr)expression;
  
              // A method invocation expression is a poly expression if all of the following are true:
              //
              // 1. The invocation appears in an assignment context or an invocation context (§5.2, §5.3).
  
              if (!appearsInAssignmentContext(expression) || appearsInInvocationContext(expression)) {
                  return false;
              }
  
              // 2. If the invocation is qualified (that is, any form of MethodInvocation except for the first), then
              //    the invocation elides TypeArguments to the left of the Identifier.
  
              if (isQualified(methodCallExpr) && !elidesTypeArguments(methodCallExpr)) {
                  return false;
              }
  
              // 3. The method to be invoked, as determined by the following subsections, is generic (§8.4.4) and has a
              //    return type that mentions at least one of the method's type parameters.
  
              //boolean condition3 =;
              throw new UnsupportedOperationException(expression.toString());
  
              // Otherwise, the method invocation expression is a standalone expression.
              //return true;
          }
          if (expression instanceof MethodReferenceExpr) {
              throw new UnsupportedOperationException(expression.toString());
          }
          if (expression instanceof ConditionalExpr) {
              throw new UnsupportedOperationException(expression.toString());
          }
          if (expression instanceof LambdaExpr) {
              return true;
          }
          return false;
      }
docs: See https://docs.oracle.com/javase/specs/jls/se8/html/jls-15.html#jls-15.2
  @return