src/vs/base/browser/ui/grid/gridview.ts/BranchNode/style
class BranchNode:	style(styles: IGridViewStyles): void {
		this._styles = styles;
		this.splitview.style(styles);

		for (const child of this.children) {
			if (child instanceof BranchNode) {
				child.style(styles);
			}
		}
	}