### Question:
JobKey extends FlowKey implements Comparable<Object> { public String toString() { return super.toString() + Constants.SEP + this.jobId.getJobIdString(); } JobKey(String cluster, String userName, String appId, long runId,
      String jobId); @JsonCreator  JobKey(@JsonProperty("cluster") String cluster,
                @JsonProperty("userName") String userName,
                @JsonProperty("appId") String appId,
                @JsonProperty("runId") long runId,
                @JsonProperty("jobId") JobId jobId);  JobKey(QualifiedJobId qualifiedJobId, String userName, String appId,
      long runId);  JobKey(JobDesc jobDesc); QualifiedJobId getQualifiedJobId(); JobId getJobId(); String toString(); @Override int compareTo(Object other); @Override boolean equals(Object other); @Override int hashCode();  }### Answer:
@Test public void testToString() { JobKey key = new JobKey("c1@local", "auser", "app", 1345L, "job_20120101000000_0001"); String expected = "c1@local" + Constants.SEP + "auser" + Constants.SEP + "app" + Constants.SEP + 1345L + Constants.SEP + "job_20120101000000_0001"; assertEquals(expected, key.toString()); }