src/vs/workbench/browser/parts/editor/sideBySideEditor.ts/SideBySideEditor/getSplitViewRatio
class SideBySideEditor:	private getSplitViewRatio(): number | undefined {
		let ratio: number | undefined = undefined;

		if (this.splitview) {
			const leftViewSize = this.splitview.getViewSize(0);
			const rightViewSize = this.splitview.getViewSize(1);

			// Only return a ratio when the view size is significantly
			// enough different for left and right view sizes
			if (Math.abs(leftViewSize - rightViewSize) > 1) {
				const totalSize = this.splitview.orientation === Orientation.HORIZONTAL ? this.dimension.width : this.dimension.height;
				ratio = leftViewSize / totalSize;
			}
		}

		return ratio;
	}