description

# insertAllBefore method Null safety

void insertAllBefore (

1. Iterable<Node> newNodes,
2. Node refChild

)

Inserts all of the nodes into this node directly before refChild.

See also:

- insertBefore

## Implementation

    void insertAllBefore(Iterable<Node> newNodes, Node refChild) {
      if (newNodes is _ChildNodeListLazy) {
        _ChildNodeListLazy otherList = newNodes;
        if (identical(otherList._this, this)) {
          throw new ArgumentError(newNodes);
        }

        // Optimized route for copying between nodes.
        for (var i = 0, len = otherList.length; i < len; ++i) {
          this.insertBefore(otherList._this.firstChild!, refChild);
        }
      } else {
        for (var node in newNodes) {
          this.insertBefore(node, refChild);
        }
      }
    }