demo/dist/demo.js
function setDataCallback(callback) {
	    var original = this._globalOptions.dataCallback;
	    this._globalOptions.dataCallback = keepOriginalCallback(original, callback);
	    return this;
	  }
function setDataCallback(callback) {
	    var original = this._globalOptions.dataCallback;
	    this._globalOptions.dataCallback = keepOriginalCallback(original, callback);
	    return this;
	  }
/*
Set the dataCallback option

@param {function} callback The callback to run which allows the
data blob to be mutated before sending
@return {Raven}