whole_func_string: function next() {
      var middleware = chain.shift();
  
      if (middleware && typeof middleware === 'function') {
        middleware.call(this, context, next);
      }
  
      return this;
    }
func_code_string: function next() {
      var middleware = chain.shift();
  
      if (middleware && typeof middleware === 'function') {
        middleware.call(this, context, next);
      }
  
      return this;
    }
func_documentation_string: Next function.
  Calls the next middleware in chain.