How to use the parchment.Scope.BLOCK_BLOT function in parchment

formatAt(index, length, name, value) {
    this.format(name, value);
  }

  insertAt(index, value, def) {
    if (typeof value === 'string' && value.endsWith('\n')) {
      const block = this.scroll.create(Block.blotName);
      this.parent.insertBefore(block, index === 0 ? this : this.next);
      block.insertAt(0, value.slice(0, -1));
    } else {
      super.insertAt(index, value, def);
    }
  }
}
BlockEmbed.scope = Scope.BLOCK_BLOT;
// It is important for cursor behavior BlockEmbeds use tags that are block level elements

function blockDelta(blot, filter = true) {
  return blot
    .descendants(LeafBlot)
    .reduce((delta, leaf) => {
      if (leaf.length() === 0) {
        return delta;
      }
      return delta.insert(leaf.value(), bubbleFormats(leaf, {}, filter));
    }, new Delta())
    .insert('\n', bubbleFormats(blot));
}

function bubbleFormats(blot, formats = {}, filter = true) {
  if (blot == null) return formats;

format(name, value) {
    if (this.savedLength !== 0) {
      super.format(name, value);
      return;
    }
    let target = this;
    let index = 0;
    while (target != null && target.statics.scope !== Scope.BLOCK_BLOT) {
      index += target.offset(target.parent);
      target = target.parent;
    }
    if (target != null) {
      this.savedLength = Cursor.CONTENTS.length;
      target.optimize();
      target.formatAt(index, Cursor.CONTENTS.length, name, value);
      this.savedLength = 0;
    }
  }