function getNodeIdsCoveredByContainerSelection (doc, sel) {
  const containerPath = sel.containerPath
  const startPos = getContainerPosition(doc, containerPath, sel.start.path[0])
  const endPos = getContainerPosition(doc, containerPath, sel.end.path[0])
  const nodeIds = doc.get(containerPath)
  return nodeIds.slice(startPos, endPos + 1)
}
Get the node ids covered by this selection.

@returns {String[]} an getNodeIds of ids