code: public static Call get(final BandwidthClient client, final String callId) throws Exception {
      	
          final String callsUri = client.getUserResourceInstanceUri(BandwidthConstants.CALLS_URI_PATH, callId);
          
          final JSONObject jsonObject = toJSONObject(client.get(callsUri, null));
          
          return new Call(client, jsonObject);
      }
docs: Convenience factory method for Call, returns a Call object given an id
  @param client the client
  @param callId the call id
  @return the call
  @throws Exception error.