code: function (context_uid, sender, receiver, channel, message, meta) {
          if (!this.api_key) throw new ChangeTipException(300);
          if (!channel) throw new ChangeTipException(301);
  
          var deferred = Q.defer(),
              data;
  
          data = {
              context_uid: context_uid,
              sender: sender,
              receiver: receiver,
              channel: channel,
              message: message,
              meta: meta
          };
  
          this._send_request(data, 'tips', null, Methods.POST, deferred);
          return deferred.promise;
      }
docs: Sends a tip via the ChangeTip API
  @param context_uid {number|string} Unique ID for this tip
  @param {number|string} sender username/identifier for the tip sender
  @param {number|string} receiver username/identifier for the tip receiever
  @param {string} channel Origin channel for this tip (twitter, github, slack, etc)
  @param {string} message Tip message. Includes amount or moniker.
  @param [meta] {Object} optional object to be sent back in result set
  @returns {promise.promise|jQuery.promise|promise|Q.promise|jQuery.ready.promise|l.promise}