DiscontinuityDetector = function(audiolet, threshold, callback) {
    AudioletNode.call(this, audiolet, 1, 1);
    this.linkNumberOfOutputChannels(0, 0);

    this.threshold = threshold || 0.2;
    if (callback) {
        this.callback = callback;
    }
    this.lastValues = [];

}
Detect discontinuities in the input stream.  Looks for consecutive samples
with a difference larger than a threshold value.

**Inputs**

- Audio

**Outputs**

- Audio

@constructor
@extends PassThroughNode
@param {Audiolet} audiolet The audiolet object.
@param {Number} [threshold=0.2] The threshold value.
@param {Function} [callback] Function called if a discontinuity is detected.