ConfigurationUtils { public static void copy(Configuration source, Configuration target) { Check.notNull(source, "source"); Check.notNull(target, "target"); for (Map.Entry<String, String> entry : source) { target.set(entry.getKey(), entry.getValue()); } }  static void copy(Configuration source, Configuration target); static void injectDefaults(Configuration source,
      Configuration target); static Configuration resolve(Configuration conf); static void load(Configuration conf, InputStream is);  }
@Test public void copy() throws Exception { Configuration srcConf = new Configuration(false); Configuration targetConf = new Configuration(false); srcConf.set("testParameter1", "valueFromSource"); srcConf.set("testParameter2", "valueFromSource"); targetConf.set("testParameter2", "valueFromTarget"); targetConf.set("testParameter3", "valueFromTarget"); ConfigurationUtils.copy(srcConf, targetConf); assertEquals("valueFromSource", targetConf.get("testParameter1")); assertEquals("valueFromSource", targetConf.get("testParameter2")); assertEquals("valueFromTarget", targetConf.get("testParameter3")); }