public final double avg()  { if (VM.VerifyAssertions) VM.assert(count > 0); return sum / count; }
public final double avg()  { if (VM.VerifyAssertions) VM._assert(count > 0); return sum / count; }
  public final double avg()  { if (VM.VerifyAssertions) VM.assert(count > 0); return sum / count; }