src/vs/workbench/contrib/debug/common/debugSource.ts/Source/constructor
class Source:	constructor(raw_: DebugProtocol.Source | undefined, sessionId: string, uriIdentityService: IUriIdentityService) {
		let path: string;
		if (raw_) {
			this.raw = raw_;
			path = this.raw.path || this.raw.name || '';
			this.available = true;
		} else {
			this.raw = { name: UNKNOWN_SOURCE_LABEL };
			this.available = false;
			path = `${DEBUG_SCHEME}:${UNKNOWN_SOURCE_LABEL}`;
		}

		this.uri = getUriFromSource(this.raw, path, sessionId, uriIdentityService);
	}