code: protected final void setInterpolator(@NonNull final Interpolator interpolator) {
          Condition.INSTANCE.ensureNotNull(interpolator, "The interpolator may not be null");
          this.interpolator = interpolator;
      }
docs: Sets the interpolator, which should be used by the animation.
  
  @param interpolator
  The interpolator, which should be set, as an instance of the type {@link
  Interpolator}. The interpolator may not be null