extensions/git/src/repository.ts/Repository/fastForwardBranch
class Repository:	async fastForwardBranch(name: string): Promise<void> {
		// Get branch details
		const branch = await this.getBranch(name);
		if (!branch.upstream?.remote || !branch.upstream?.name || !branch.name) {
			return;
		}

		try {
			// Fast-forward the branch if possible
			const options = { remote: branch.upstream.remote, ref: `${branch.upstream.name}:${branch.name}` };
			await this.run(Operation.Fetch, async () => this.repository.fetch(options));
		} catch (err) {
			if (err.gitErrorCode === GitErrorCodes.BranchFastForwardRejected) {
				return;
			}

			throw err;
		}
	}