assertFileExistence(dir, filename, true);

        File file = new File(dir, filename);

        String contents = FileUtils.fileRead(file, encoding);

        assertEquals(contentsTest, contents);
    }

    public File createFile(File dir, String filename, String contents, String encoding) throws IOException {
        File file = new File(dir, filename);

        file.getParentFile().mkdirs();

   * attribute values and in most elements' text contents, provided that the HTML
   * document's character encoding can encode any non-ASCII code points in the input (as UTF-8 and
   * other Unicode encodings can).
   *
   * <p><b>Note:</b> This escaper only performs minimal escaping to make content structurally
   * compatible with HTML. Specifically, it does not perform entity replacement (symbolic or

   * safely be included in an XML document as element content. See section <a
   * href="http://www.w3.org/TR/2008/REC-xml-20081126/#syntax">2.4</a> of the XML specification.
   *
   * <p><b>Note:</b> Double and single quotes are not escaped, so it is <b>not safe</b> to use this
   * escaper to escape attribute values. Use {@link #xmlContentEscaper} if the output can appear in
   * element content or {@link #xmlAttributeEscaper} in attribute values.
   *

  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], Arrays.asList(contents));
  }

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> from(Collection<? extends E> contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], contents);
  }

  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], Arrays.asList(contents));
  }

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> from(Collection<? extends E> contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], contents);
  }

            return this;
        }

        public XmlWriterRequestBuilder<T> content(T content) {
            this.content = content;
            return this;
        }

        public XmlWriterRequest<T> build() {
            return new DefaultXmlWriterRequest<>(path, outputStream, writer, content);
        }

        private static class DefaultXmlWriterRequest<T> implements XmlWriterRequest<T> {

            if (writer != null) {
                new MavenStaxWriter().write(writer, content);
            } else if (outputStream != null) {
                new MavenStaxWriter().write(outputStream, content);
            } else {
                try (OutputStream os = Files.newOutputStream(path)) {
                    new MavenStaxWriter().write(outputStream, content);
                }
            }
        } catch (Exception e) {

            if (writer != null) {
                new MavenStaxWriter().write(writer, content);
            } else if (outputStream != null) {
                new MavenStaxWriter().write(outputStream, content);
            } else {
                try (OutputStream os = Files.newOutputStream(path)) {
                    new MavenStaxWriter().write(outputStream, content);
                }
            }
        } catch (Exception e) {

        }
    }

    @Override
    public void write(XmlWriterRequest<PersistedToolchains> request) throws XmlWriterException {
        nonNull(request, "request");
        PersistedToolchains content = Objects.requireNonNull(request.getContent(), "content");
        OutputStream outputStream = request.getOutputStream();
        Writer writer = request.getWriter();
        if (writer == null && outputStream == null) {

        }
    }

    @Override
    public void write(XmlWriterRequest<PersistedToolchains> request) throws XmlWriterException {
        nonNull(request, "request");
        PersistedToolchains content = Objects.requireNonNull(request.getContent(), "content");
        OutputStream outputStream = request.getOutputStream();
        Writer writer = request.getWriter();
        if (writer == null && outputStream == null) {