code: function setBreadcrumbCallback(callback) {
  	    var original = this._globalOptions.breadcrumbCallback;
  	    this._globalOptions.breadcrumbCallback = keepOriginalCallback(original, callback);
  	    return this;
  	  }
docs: /*
  Set the breadcrumbCallback option
  
  @param {function} callback The callback to run which allows filtering
  or mutating breadcrumbs
  @return {Raven}