@Test
public void fromCharSequence() {

    final Optional<ReferencePlaceholder> referencePlaceholder =
            ReferencePlaceholder.fromCharSequence("{{ref:things/" + THING_ID + "/policyId}}");
    assertThat(referencePlaceholder).isPresent();
    assertThat(referencePlaceholder.get().getReferencedEntityId().toString()).isEqualTo(THING_ID.toString());
    DittoJsonAssertions.assertThat(referencePlaceholder.get().getReferencedField())
            .isEqualTo(                JsonPointer.of("policyId"));
    assertThat(referencePlaceholder.get().getReferencedEntityType()).isEqualTo(
            ReferencePlaceholder.ReferencedEntityType.THINGS);
}