### Question:
ManagedResourceProvider implements ResourceProvider { protected File validateFile( File file ) { return file != null && file.exists() && file.isFile() ? file : null; }  void setBundleContext( BundleContext bundleContext ); void init(); @Override File getManagedResourceFolder(); @Override File provideFolder( Bundle bundle, String relativePath ); @Override File provideFolder( String bundleName, String relativePath ); @Override File provideFile( Bundle bundle, String relativePath ); @Override File provideFile( String bundleName, String relativePath ); static String MANAGED_RESOURCES_DIR; }### Answer:
@Test public void validateFileTest() { assertNull( resourceProvider.validateFile( null ) ); File file = mock( File.class ); doReturn( false ).when( file ).exists(); assertNull( resourceProvider.validateFile( null ) ); doReturn( true ).when( file ).exists(); doReturn( false ).when( file ).isDirectory(); assertNull( resourceProvider.validateFile( null ) ); doReturn( true ).when( file ).isFile(); assertEquals( file, resourceProvider.validateFile( file ) ); }