code: public static Call create(final BandwidthClient client, final Map <String, Object>params) 
              throws Exception {
      	assert (client != null && params != null);
          final String callUri = client.getUserResourceUri(BandwidthConstants.CALLS_URI_PATH);
      	final RestResponse response = client.post(callUri, params);
  
          // success here, otherwise an exception is generated
      	final String callId = response.getLocation().substring(client.getPath(callUri).length() + 1);
  
          return get(client, callId);
      }
docs: Dials a call, from a phone number to a phone number.
  @param client the client
  @param params the call params
  @return the call
  @throws IOException unexpected error.