String separator = System.getProperty("line.separator");
    sink.writeLines(lines);

    assertContainsExpectedLines(separator);
  }

  public void testWriteLines_specificSeparator() throws IOException {
    String separator = "\r\n";
    sink.writeLines(lines, separator);

    assertContainsExpectedLines(separator);
  }

   * Returns a splitter that uses the given single-character separator. For example, {@code
   * Splitter.on(',').split("foo,,bar")} returns an iterable containing {@code ["foo", "", "bar"]}.
   *
   * @param separator the character to recognize as a separator
   * @return a splitter, with default settings, that recognizes that separator
   */
  public static Splitter on(char separator) {
    return on(CharMatcher.is(separator));
  }

    String separator = System.getProperty("line.separator");
    sink.writeLines(lines);

    assertContainsExpectedLines(separator);
  }

  public void testWriteLines_specificSeparator() throws IOException {
    String separator = "\r\n";
    sink.writeLines(lines, separator);

    assertContainsExpectedLines(separator);
  }

<img src="/img/tutorial/generate-clients/image05.png">

## Application FastAPI avec des tags { #fastapi-app-with-tags }

Dans de nombreux cas, votre application FastAPI sera plus grande, et vous utiliserez probablement des tags pour séparer différents groupes de *chemins d'accès*.

Par exemple, vous pourriez avoir une section pour les **items** et une autre section pour les **users**, et elles pourraient être séparées par des tags :

    sink.writeLines(ImmutableList.of("foo", "bar", "baz"));
    String separator = System.getProperty("line.separator");
    assertThat(sink.getString())
        .isEqualTo("foo" + separator + "bar" + separator + "baz" + separator);
  }

  public void testWriteLines_stream() throws IOException {
    sink.writeLines(ImmutableList.of("foo", "bar", "baz").stream());
    String separator = LINE_SEPARATOR.value();
    assertThat(sink.getString())

    public BaseEncoding withSeparator(String separator, int afterEveryChars) {
      for (int i = 0; i < separator.length(); i++) {
        checkArgument(
            !alphabet.matches(separator.charAt(i)),
            "Separator (%s) cannot contain alphabet characters",
            separator);
      }
      if (paddingChar != null) {
        checkArgument(
            separator.indexOf(paddingChar) < 0,

    sink.writeLines(ImmutableList.of("foo", "bar", "baz"));
    String separator = System.getProperty("line.separator");
    assertThat(sink.getString())
        .isEqualTo("foo" + separator + "bar" + separator + "baz" + separator);
  }

  public void testWriteLines_stream() throws IOException {
    sink.writeLines(ImmutableList.of("foo", "bar", "baz").stream());
    String separator = LINE_SEPARATOR.value();
    assertThat(sink.getString())

  OS_ARCH("os.arch"),

  /** Operating system version. */
  OS_VERSION("os.version"),

  /** File separator ("/" on UNIX). */
  FILE_SEPARATOR("file.separator"),

  /** Path separator (":" on UNIX). */
  PATH_SEPARATOR("path.separator"),

  /** Line separator ("\n" on UNIX). */
  LINE_SEPARATOR("line.separator"),

  /** User's account name. */
  USER_NAME("user.name"),

  /** User's home directory. */

   * the operating system's default line separator. This method is equivalent to {@code
   * writeLines(lines, System.getProperty("line.separator"))}.
   *
   * @throws IOException if an I/O error occurs while writing to this sink
   */
  public void writeLines(Iterable<? extends CharSequence> lines) throws IOException {
    writeLines(lines, System.getProperty("line.separator"));
  }

  /**

     *
     * @param str
     *            the string
     * @param separator
     *            the separator
     * @return the resulting string
     */
    public static String substringFromLast(final String str, final String separator) {
        if (isEmpty(str) || isEmpty(separator)) {
            return str;
        }