Fail to introduce method

### Apache NetBeans version

Apache NetBeans 21

### What happened

When I tried to perform "introduce method" refactoring on "int b= 10;" using refactoring tool in NetBeans, it displayed a warning and failed to do the refactoring.

### Language / Project Type / NetBeans Component

Java Maven Project Java Application

### How to reproduce

Input Program:
```java
public interface I1 {
int foo(int a);
}

interface I2 {
I1 i1= (a) -> {
int b= 10;
return a + b;
};
}
```

Steps:
Select "int b = 10;"
Refactor -> Introduce -> Method

Actual Result:
a warning: "Invalid Selection."

Expected Result: (from Refactoring tool of IntelliJ)
```java
public interface I1 {
int foo(int a);
}

interface I2 {
I1 i1 = (a) -> {
int b = getB();
return a + b;
};

private static int getB() {
int b = 10;
return b;
}
}
```

### Did this work correctly in an earlier version?

No / Don't know

### Operating System

Windows 11

### JDK

22.0.1

### Apache NetBeans packaging

Apache NetBeans provided installer

### Anything else

It always occurs.

### Are you willing to submit a pull request?

No

Reproduce the Java Maven example in Apache NetBeans 21 by selecting `int b = 10;` and choosing Refactor → Introduce → Method. Trace the Introduce Method refactoring flow for this selection context; done means the selection is accepted and the extracted method matches the expected result shown in the issue.

Written by the indexing model from the issue text.