@Test
  public void testMasterCoprocessorsReported() {
    // HBASE 4070: Improve region server metrics to report loaded coprocessors
    // to master: verify that the master is reporting the correct set of
    // loaded coprocessors.
    final String loadedMasterCoprocessorsVerify = "[" + masterCoprocessor.getSimpleName() + "]";
    String loadedMasterCoprocessors =
      java.util.Arrays.toString(TEST_UTIL.getHBaseCluster().getMaster().getMasterCoprocessors());
    assertEquals(loadedMasterCoprocessorsVerify, loadedMasterCoprocessors);
  }
return the subset of all regionservers (actually returns set of ServerLoads) which host some
region in a given table. used by assertAllRegionServers() below to test reporting of loaded
coprocessors.
@param tableName : given table.
@return subset of all servers.
hbase-endpoint/src/test/java/org/apache/hadoop/hbase/coprocessor/TestClassLoading.java