code: function setDataCallback(callback) {
  	    var original = this._globalOptions.dataCallback;
  	    this._globalOptions.dataCallback = keepOriginalCallback(original, callback);
  	    return this;
  	  }
docs: /*
  Set the dataCallback option
  
  @param {function} callback The callback to run which allows the
  data blob to be mutated before sending
  @return {Raven}