code: function transformData(data, headers, status, fns) {
    if (isFunction(fns))
      return fns(data, headers, status);
  
    forEach(fns, function(fn) {
      data = fn(data, headers, status);
    });
  
    return data;
  }
docs: Chain all given functions
  
  This function is used for both request and response transforming
  
  @param {*} data Data to transform.
  @param {function(string=)} headers HTTP headers getter fn.
  @param {number} status HTTP status code of the response.
  @param {(Function|Array.<Function>)} fns Function or an array of functions.
  @returns {*} Transformed data.