code: public static IncrementalScopeCreator getInstance(AbstractCompiler compiler) {
      IncrementalScopeCreator creator = compiler.getScopeCreator();
      if (creator == null) {
        creator = new IncrementalScopeCreator(compiler);
        compiler.putScopeCreator(creator);
      }
      return creator;
    }
docs: Get an instance of the ScopeCreator