Context { public Context getChild(String name) { return children.get(name); }  Set<String> getKeys(); String get(String key); void put(String key, String value); Map<String, Context> getChildren(); Context getChild(String name); Context createChild(String name); void remove(String nameOrKey); void setId(String id); String getId(); @Override String toString();  }
@Test public void testGetNonExistingChild_shouldReturnNull() throws Exception { assertThat(context.getChild("non-existing"), nullValue()); }