title: Coreplot animations with identifier
body: <p>I am trying to perform multiple animations in coreplot.
  To run first animation I've used: </p>
  
  <pre><code> [CPTAnimation animate:plotSpace
                   property:@"xRange"
              fromPlotRange:oldXrange
                toPlotRange:newxRange
                   duration:1.0
                  withDelay:0
             animationCurve:CPTAnimationCurveCubicInOut
                   delegate:self];
  </code></pre>
  
  <p>and implemented <code>CPTAnimationDelegate</code>:</p>
  
  <pre><code>-(void)animationDidFinish:(nonnull CPTAnimationOperation *)operation {
      CPTPlotRange *newxRange = [CPTPlotRange
                                 plotRangeWithLocation:@500
                                 length:@100];
  
      [self performSecondAnimationWithnewXRange:newXrange];}
  </code></pre>
  
  <p>I want, however, to run multiple animations using identifier. I've tried creatingPTAnimationOperation, but don't know how to fire it:</p>
  
  <pre><code>CPTAnimationOperation* animation1 = [[CPTAnimationOperation alloc] init];
  CPTAnimationPeriod *period = [CPTAnimationPeriod periodWithStartPlotRange:plotSpace.xRange
                                                                           endPlotRange:newxRange
                                                                               duration:3.0
                                                                              withDelay:0.0];
  animation1.identifier = @"animation1ID";
  animation1.period = period;
  </code></pre>
  
  <p>How do I actually start the animation, so in delegate I could check it's ID?</p>