code: private void pushScope(AbstractScope<?, ?> s, boolean quietly) {
      checkNotNull(curNode);
      scopes.push(s);
      recordScopeRoot(s.getRootNode());
      if (!quietly && scopeCallback != null) {
        scopeCallback.enterScope(this);
      }
    }
docs: Creates a new scope (e.g. when entering a function).
  @param quietly Don't fire an enterScope callback.