NumberKeyframeTrack constructor
name - identifier for the KeyframeTrack.
times - array of keyframe times.
values - values for the keyframes at the times specified.
[interpolation] - the type of interpolation to use. See
Animation Constants for possible values. Default is
Animation InterpolateLinear.
Implementation
/// [Animation Constants] for possible values. Default is
/// [Animation InterpolateLinear].
NumberKeyframeTrack(super.name, super.times, super.values, [super.interpolation]){
valueTypeName = "number";
}