import org.apache.hadoop.hbase.rest.MetricsRESTSource; //导入依赖的package包/类
public MetricsRESTSource getSource() {
  return source;
}
 

import org.apache.hadoop.hbase.rest.MetricsRESTSource; //导入依赖的package包/类
public MetricsREST() {
   source = CompatibilitySingletonFactory.getInstance(MetricsRESTSource.class);
}
 

import org.apache.hadoop.hbase.rest.MetricsRESTSource; //导入依赖的package包/类
@Test(expected=RuntimeException.class)
public void testGetInstanceNoHadoopCompat() throws Exception {
  //This should throw an exception because there is no compat lib on the class path.
  CompatibilitySingletonFactory.getInstance(MetricsRESTSource.class);
}
 

import org.apache.hadoop.hbase.rest.MetricsRESTSource; //导入依赖的package包/类
@Test
public void ensureCompatRegistered() throws Exception {
  assertNotNull(CompatibilitySingletonFactory.getInstance(MetricsRESTSource.class));
  assertTrue(CompatibilitySingletonFactory.getInstance(MetricsRESTSource.class) instanceof MetricsRESTSourceImpl);
}