public NewIssuesNotification newNewIssuesNotification(Map<String, UserDto> assigneesByUuid) {
    verifyAssigneesByUuid(assigneesByUuid);
    return new NewIssuesNotification(new DetailsSupplierImpl(assigneesByUuid));
  }
@Test
  public void newNewIssuesNotification_DetailsSupplier_getUserNameByUuid_always_returns_empty_if_map_argument_is_empty() {
    NewIssuesNotification underTest = this.underTest.newNewIssuesNotification(emptyMap());

    DetailsSupplier detailsSupplier = readDetailsSupplier(underTest);
    assertThat(detailsSupplier.getUserNameByUuid("foo")).isEmpty();
  }