lso holds an optional <code><a href="../../../reference/android/animation/TimeInterpolator.html">TimeInterpolator</a></code>
 object, which defines the time interpolation over the intervalue preceding the keyframe.

 <p>The Keyframe class itself is abstract. The type-specific factory methods will return
 a subclass of Keyframe specific to the type of value being stored. This is done to improve
 performance when dealing with the most common cases (e.g., <code>float</code> and
 <code>int</code> values). Other