code: function apply_data(query, files) {
    if(startCb){
      startCb();
    }
    if (query !== undefined) {
      if (this.method === 'get') {
        this.request = this.request.query(query)
      } else {
        this.request = this.request.send(query)
      }
    }
  
    if (files !== undefined) {
      if (files instanceof FormData) {
        this.request = this.request.send(files)
      } else {
        Object.keys(files).forEach((key) => {
          this.request = this.request.attach(key, files[key])
        })
      }
    }
  }
docs: Applies data to the this.request superagent object. Works with query params or
  file attachments.
  
  @param {Object} query  - Any parameters to be sent in the query string for GET requests or in the req body for others
  @param {Object/FormData} files  - Key / value mapped object containing file paths for uploads, or a FormData object if it's coming from the browser
  @private