@VisibleForTesting
  boolean isIntact() {
    for (int i = 1; i < size; i++) {
      if (!heapForIndex(i).verifyIndex(i)) {
        return false;
      }
    }
    return true;
  }
@VisibleForTesting
  boolean isIntact() {
    for (int i = 1; i < size; i++) {
      if (!heapForIndex(i).verifyIndex(i)) {
        return false;
      }
    }
    return true;
  }
@ VisibleForTesting boolean isIntact ( ) { for ( int i = 1 ; i < size ; i ++ ) { if ( ! heapForIndex ( i ) . verifyIndex ( i ) ) { return false ; } } return true ; }
Returns {@code true} if the MinMax heap structure holds. This is only used in testing.

<p>TODO(kevinb): move to the test class?
Returns { @code true } if the MinMax heap structure holds . This is only used in testing .