code: function (opts, id) {
          let uri = this.classUrl
          if (id) {
            uri += '/' + id
          }
  
          return new Promise(function (resolve, reject) {
            new Requestor({ api_version: instance.api_version }).request({
              method: 'post',
              url: [Conekta.api_base, uri].join(''),
              data: opts.data || {},
              next: function (error, response) {
                if (!error) {
                  response = this.listObjectsToArray(response)
                  this._json = response
                  this._id = response.id
                  this.build_children()
                }
                if (opts.next !== undefined) {
                  opts.next(error, this)
                } else {
                  if (error) {
                    reject(error)
                  } else {
                    resolve(this)
                  }
                }
              }.bind(this)
            })
          }.bind(this))
        }
docs: /*
  Method to build POST calls