in src/commands/createChildNode.ts [8:14]
export async function createChildNode(actionContext: IActionContext, tree: AzureTreeDataProvider, expectedContextValue: string, node?: AzureParentTreeItem): Promise<void> {
if (!node) {
node = <AzureParentTreeItem>await tree.showTreeItemPicker(expectedContextValue);
}
await node.createChild(actionContext);
}