private void suggestFromOptionalContent(@NotNull VariableKind variableKind,
                                          @NotNull PsiClassType classType,
                                          @NotNull Collection<? super String> suggestions) {
    final PsiType optionalContent = extractOptionalContent(classType);
    if (optionalContent == null) return;

    final Collection<String> contentSuggestions = doSuggestNamesByType(optionalContent, variableKind);
    suggestions.addAll(contentSuggestions);
    for (String s : contentSuggestions) {
      suggestions.add("optional" + StringUtil.capitalize(s));
    }
  }
private void suggestFromOptionalContent(@NotNull VariableKind variableKind,
                                          @NotNull PsiClassType classType,
                                          @NotNull Collection<? super String> suggestions)