src/vs/code/electron-main/auth.ts/ProxyAuthHandler/resolveProxyCredentials
class ProxyAuthHandler:	private async resolveProxyCredentials(authInfo: AuthInfo): Promise<Credentials | undefined> {
		this.logService.trace('auth#resolveProxyCredentials (proxy) - enter');

		try {
			const credentials = await this.doResolveProxyCredentials(authInfo);
			if (credentials) {
				this.logService.trace('auth#resolveProxyCredentials (proxy) - got credentials');

				return credentials;
			} else {
				this.logService.trace('auth#resolveProxyCredentials (proxy) - did not get credentials');
			}
		} finally {
			this.logService.trace('auth#resolveProxyCredentials (proxy) - exit');
		}

		return undefined;
	}