src/vs/workbench/common/editor/diffEditorInput.ts/DiffEditorInput/computeLabel
class DiffEditorInput:	private computeLabel(originalLabel: string | undefined, modifiedLabel: string | undefined, separator = ' - '): string | undefined {
		if (!originalLabel || !modifiedLabel) {
			return undefined;
		}

		if (originalLabel === modifiedLabel) {
			return modifiedLabel;
		}

		return `${originalLabel}${separator}${modifiedLabel}`;
	}