public void registerClient(SonarLintClient sonarLintClient) {
    clients.add(sonarLintClient);
    sonarLintClient.scheduleHeartbeat();
    sonarLintClient.addListener(new SonarLintClientEventsListener(sonarLintClient));
    LOG.debug("Registering new SonarLint client");
  }
@Test
  public void registerClient_whenCalledFirstTime_addsAsyncListenerToClient() {
    SonarLintClient client = mock(SonarLintClient.class);
    underTest.registerClient(client);

    verify(client).addListener(any());
  }