public Class<?>[] getCallingClasses() {
    return getClassContext();
  }
Provides classes (and not just class names) of the call stack.
<p>
NOTE: Extending SecurityManager is a convenient hack that works for Java 8 through 19.
StackWalker would be preferred when the compatibility level gets raised to Java 9.
value-processor/src/org/immutables/processor/CallStack.java