code: function( timeOffset ) {
  
  		if( timeOffset !== 0.0 ) {
  
  			var times = this.times;
  
  			for( var i = 0, n = times.length; i !== n; ++ i ) {
  
  				times[ i ] += timeOffset;
  
  			}
  
  		}
  
  		return this;
  
  	}
docs: move all keyframes either forwards or backwards in time