@NotNull
  public final @NlsSafe String getTargetPrefixSeparatorValue() {
    final GenericAttributeValue<String> separator = getTargetPrefixSeparator();
    if (separator == null) {
      return DEFAULT_SEPARATOR;
    }
    final String separatorValue = separator.getStringValue();
    return separatorValue != null? separatorValue : DEFAULT_SEPARATOR;
  }
@NotNull
  public final @NlsSafe String getTargetPrefixSeparatorValue()