code: public DependencyCustomizer ifAnyMissingClasses(String... classNames) {
  		return new DependencyCustomizer(this) {
  			@Override
  			protected boolean canAdd() {
  				for (String className : classNames) {
  					try {
  						DependencyCustomizer.this.loader.loadClass(className);
  					}
  					catch (Exception ex) {
  						return true;
  					}
  				}
  				return false;
  			}
  		};
  	}
docs: Create a nested {@link DependencyCustomizer} that only applies if any of the
  specified class names are not on the class path.
  @param classNames the class names to test
  @return a nested {@link DependencyCustomizer}