### Question:
FlowKey extends AppKey implements Comparable<Object> { public String toString() { return super.toString() + Constants.SEP + this.getRunId(); } @JsonCreator  FlowKey(@JsonProperty("cluster") String cluster,
                 @JsonProperty("userName") String userName,
                 @JsonProperty("appId") String appId,
                 @JsonProperty("runId") long runId);  FlowKey(FlowKey toCopy); long getEncodedRunId(); static long encodeRunId(long timestamp); long getRunId(); String toString(); @Override int compareTo(Object other); @Override boolean equals(Object other); @Override int hashCode();  }### Answer:
@Test public void testToString() { FlowKey key = new FlowKey("c1@local", "auser", "app", 1345L); String expected = "c1@local" + Constants.SEP + "auser" + Constants.SEP + "app" + Constants.SEP + 1345L; assertEquals(expected, key.toString()); }