@Override
  public @NonNull EntityStatementJWS fetchEntityConfiguration(URI entityUrl) {
    return entityStatementCache.computeIfAbsent(
        entityUrl.toString(), k -> delegate.fetchEntityConfiguration(entityUrl));
  }
@Test
  void fetchEntityConfiguration() {
    var uri = URI.create("https://example.com");

    var expected = new EntityStatementJWS(null, null);
    when(delegate.fetchEntityConfiguration(uri)).thenReturn(expected);

    // when
    var got = sut.fetchEntityConfiguration(uri);

    // then
    verify(delegate).fetchEntityConfiguration(uri);
    assertEquals(expected, got);
  }