src/vs/base/browser/ui/splitview/splitview.ts/SplitView/resizeView
class SplitView:	resizeView(index: number, size: number): void {
		if (this.state !== State.Idle) {
			throw new Error('Cant modify splitview');
		}

		this.state = State.Busy;

		if (index < 0 || index >= this.viewItems.length) {
			return;
		}

		const indexes = range(this.viewItems.length).filter(i => i !== index);
		const lowPriorityIndexes = [...indexes.filter(i => this.viewItems[i].priority === LayoutPriority.Low), index];
		const highPriorityIndexes = indexes.filter(i => this.viewItems[i].priority === LayoutPriority.High);

		const item = this.viewItems[index];
		size = Math.round(size);
		size = clamp(size, item.minimumSize, Math.min(item.maximumSize, this.size));

		item.size = size;
		this.relayout(lowPriorityIndexes, highPriorityIndexes);
		this.state = State.Idle;
	}