### Question:
CreateProjectCommand extends RootCommand<Void> { @JsonProperty public String projectName() { return projectName; } @JsonCreator  CreateProjectCommand(@JsonProperty("timestamp") @Nullable Long timestamp,
                         @JsonProperty("author") @Nullable Author author,
                         @JsonProperty("projectName") String projectName); @JsonProperty String projectName(); @Override boolean equals(Object obj); @Override int hashCode();  }### Answer:
@Test void backwardCompatibility() throws Exception { final CreateProjectCommand c = (CreateProjectCommand) Jackson.readValue( '{' + " \"type\": \"CREATE_PROJECT\"," + " \"projectName\": \"foo\"" + '}', Command.class); assertThat(c.author()).isEqualTo(Author.SYSTEM); assertThat(c.timestamp()).isNotZero(); assertThat(c.projectName()).isEqualTo("foo"); }