code: public void completeTransfer(
              String connId,
              String parentConnId,
              KeyValueCollection reasons,
              KeyValueCollection extensions
      ) throws WorkspaceApiException {
          try {
              VoicecallsidcompletetransferData completeData = new VoicecallsidcompletetransferData();
              completeData.setParentConnId(parentConnId);
              completeData.setReasons(Util.toKVList(reasons));
              completeData.setExtensions(Util.toKVList(extensions));
              CompleteTransferData data = new CompleteTransferData();
              data.data(completeData);
  
              ApiSuccessResponse response = this.voiceApi.completeTransfer(connId, data);
              throwIfNotOk("completeTransfer", response);
          } catch (ApiException e) {
              throw new WorkspaceApiException("completeTransfer failed.", e);
          }
      }
docs: Complete a previously initiated two-step transfer using the provided IDs.
  @param connId The connection ID of the consult call (established).
  @param parentConnId The connection ID of the parent call (held).
  @param reasons Information on causes for, and results of, actions taken by the user of the current DN. For details about reasons, refer to the [*Genesys Events and Models Reference Manual*](https://docs.genesys.com/Documentation/System/Current/GenEM/Reasons). (optional)
  @param extensions Media device/hardware reason codes and similar information. For details about extensions, refer to the [*Genesys Events and Models Reference Manual*](https://docs.genesys.com/Documentation/System/Current/GenEM/Extensions). (optional)