code: public GVRAnimation setDuration(float start, float end)
      {
          if(start>end || start<0 || end>mDuration){
              throw new IllegalArgumentException("start and end values are wrong");
          }
          animationOffset =  start;
          mDuration = end-start;
          return this;
      }
docs: Sets the duration for the animation to be played.
  
  @param start the animation will start playing from the specified time
  @param end the animation will stop playing at the specified time
  
  @return {@code this}, so you can chain setProperty() calls.
  @throws IllegalArgumentException
  If {@code start} is either negative value, greater than
  {@code end} value or {@code end} is greater than duration