### Question:
DefaultExplicitIndexProvider implements IndexProviders, ExplicitIndexProvider { @Override public boolean unregisterIndexProvider( String name ) { IndexImplementation removed = indexProviders.remove( name ); return removed != null; }  @Override void registerIndexProvider( String name, IndexImplementation index ); @Override boolean unregisterIndexProvider( String name ); @Override IndexImplementation getProviderByName( String name ); @Override Iterable<IndexImplementation> allIndexProviders();  }### Answer:
@Test void unregisterIndexProvider() { IndexImplementation index = mock( IndexImplementation.class ); String testProviderName = "b"; provider.registerIndexProvider( testProviderName, index ); assertTrue( provider.unregisterIndexProvider( testProviderName ) ); }
@Test void removeNotExistentProvider() { assertFalse( provider.unregisterIndexProvider( "c" ) ); }