getSegmentData(allowDeleteOnSingleUse = true) {
    const ret = this.segmentData;
    if (allowDeleteOnSingleUse && this.removeSegmentDataOnGet) {
      this.segmentData = null;
    }
    return ret;
  }
Return the segment data.

@param {boolean=} allowDeleteOnSingleUse
@return {?BufferSource}
@export