extensions/git/src/git.ts/Repository/diffBetween
class Repository:	async diffBetween(ref1: string, ref2: string, path?: string): Promise<string | Change[]> {
		const range = `${ref1}...${ref2}`;
		if (!path) {
			return await this.diffFiles(false, range);
		}

		const args = ['diff', range, '--', sanitizePath(path)];
		const result = await this.exec(args);

		return result.stdout.trim();
	}