process method

@override O process(I input)

处理输入并返回结果

Implementation

@override
O process(I input) {
  if (index >= interceptors.length) {
    throw AssertionError("index$index >= ${interceptors.length}");
  }
  var next = RealInterceptorChain(interceptors, input, index: index + 1);
  return interceptors[index].intercept(next);
}