insert method

@override void insert(int index, int count)

Inserts count new consecutive indices starting from index into indices, at random positions.

Implementation

@override
void insert(int index, int count) {
  // Offset indices after insertion point.
  for (var i = 0; i < indices.length; i++) {
    if (indices[i] >= index) {
      indices[i] += count;
    }
  }
  // Insert new indices at random positions after currentIndex.
  final newIndices = List.generate(count, (i) => index + i);
  for (var newIndex in newIndices) {
    final insertionIndex = _random.nextInt(indices.length + 1);
    indices.insert(insertionIndex, newIndex);
  }
}