@Override
  public final boolean getAllPossibleValues(List<Completion> completions, Class<?> targetType,
      String existingData, String optionContext, MethodTarget target) {
    Set<String> values = getCompletionValues();

    for (String v : values) {
      completions.add(new Completion(v));
    }

    return !completions.isEmpty();
  }
Base class for all converters that use Strings
geode-gfsh/src/main/java/org/apache/geode/management/internal/cli/converters/BaseStringConverter.java