public boolean applicable(Context context) {
    return false;
  }
Determines whether this Extension applies to the given context. If an Extension returns {@code
false} for a given class, it will not be called again during the processing of that class. An
Extension can return {@code true} and still choose not to generate any code for the class, by
returning {@code null} from {@link #generateClass}. That is often a more flexible approach.

@param context The Context of the code generation for this class.
value/src/main/java/com/google/auto/value/extension/AutoValueExtension.java