How to use the fabric-common.Client function in fabric-common

async (channel_name, chaincode_name) => {
			const step = 'NodeSDK-Base Discovery';
			testUtil.logMsg(format('\n\n%s - STARTING\n', step));
			try {
				const user = getUser();
				const client = new Client('myclient');
				const channel = client.newChannel(channel_name);
				const tlsEnrollment = await getTLS_enrollment(user);
				client.setTlsClientCertAndKey(tlsEnrollment.cert, tlsEnrollment.key);
				const idx = client.newIdentityContext(user);
				const peer1_endpoint =  client.newEndpoint({
					url: 'grpcs://localhost:7051',
					pem: getPeer1_pem(),
					'ssl-target-name-override': 'peer0.org1.example.com'
				});

				// ----- D I S C O V E R Y -----
				const discovery = channel.newDiscoveryService('mydiscovery');
				const discoverer = client.newDiscoverer('peer1-discovery');

				try {
					testUtil.logMsg(format('\n\n%s TEST 1 - config - START\n', step));

async (chaincode_name, channel_name) => {
			const step = 'NodeSDK-Base Discovery Endorsement';
			testUtil.logMsg(format('\n\n%s - STARTING\n', step));
			try {
				const user = getUser();
				const client = new Client('myclient');
				const channel = client.newChannel(channel_name);
				const tlsEnrollment = await getTLS_enrollment(user);
				client.setTlsClientCertAndKey(tlsEnrollment.cert, tlsEnrollment.key);
				const idx = client.newIdentityContext(user);
				// application must know the discovery peer's connection information
				const peer1_endpoint =  client.newEndpoint({
					url: 'grpcs://localhost:7051',
					pem: getPeer1_pem(),
					'ssl-target-name-override': 'peer0.org1.example.com'
				});

				const discovery = channel.newDiscoveryService('mydiscovery');
				const discoverer = client.newDiscoverer('peer1-discovery');
				const event_service = channel.newEventService('myevent_service');

				try {