code: public void logout() throws WorkspaceApiException {
          try {
              ApiSuccessResponse response = this.voiceApi.logoutVoice(null);
              throwIfNotOk("voiceLogout", response);
          } catch (ApiException e) {
              throw new WorkspaceApiException("voiceLogout failed", e);
          }
      }
docs: Logout the current agent on the voice channel. This request is typically paired with `login()` - together
  they let you login/logout an agent on the voice channel without logging out of the entire session.