var whitespace = false
      afterBoundaryLoop@while (true) {
        when (source.select(afterBoundaryOptions)) {
          0 -> {
            // "\r\n": We've found a new part.
            partCount++
            break@afterBoundaryLoop
          }

          1 -> {
            // "--": No more parts.

   * of several definitions of "whitespace"</a>.)
   *
   * <p>All Unicode White_Space characters are on the BMP and thus supported by this API.
   *
   * <p><b>Note:</b> as the Unicode definition evolves, we will modify this matcher to keep it up to
   * date.
   *
   * @since 19.0 (since 1.0 as constant {@code WHITESPACE})
   */
  public static CharMatcher whitespace() {
    return Whitespace.INSTANCE;
  }

   * element content or {@link #xmlAttributeEscaper} in attribute values.
   *
   * <p>This escaper substitutes {@code 0xFFFD} for non-whitespace control characters and the
   * character values {@code 0xFFFE} and {@code 0xFFFF} which are not permitted in XML. For more
   * detail see section <a href="http://www.w3.org/TR/2008/REC-xml-20081126/#charsets">2.2</a> of

    val headers =
      Headers
        .Builder()
        .add("foo: bar")
        .add(" foo: baz") // Name leading whitespace is trimmed.
        .add("foo : bak") // Name trailing whitespace is trimmed.
        .add("\tkey\t:\tvalue\t") // '\t' also counts as whitespace
        .add("ping:  pong  ") // Value whitespace is trimmed.
        .add("kit:kat") // Space after colon is not required.
        .build()

    /**
     * Process a single line: remove comments, trim whitespace, and replace placeholders.
     */
    private static String processLine(String line, String mavenProjectBasedir) {
        // Remove comments
        int commentIndex = line.indexOf('#');
        if (commentIndex >= 0) {
            line = line.substring(0, commentIndex);
        }

        // Trim whitespace
        line = line.trim();

Fixer tool expects comments that follow specific pattern:

- For hash-style comments: comment starts with `# ` (hash following by whitespace) in the beginning of the string or after a whitespace.
- For slash-style comments: comment starts with `// ` (two slashes following by whitespace) in the beginning of the string or after a whitespace.

If comment doesn't follow this pattern, fixer tool will not preserve it.

```python
#Function declaration

   * of several definitions of "whitespace"</a>.)
   *
   * <p>All Unicode White_Space characters are on the BMP and thus supported by this API.
   *
   * <p><b>Note:</b> as the Unicode definition evolves, we will modify this matcher to keep it up to
   * date.
   *
   * @since 19.0 (since 1.0 as constant {@code WHITESPACE})
   */
  public static CharMatcher whitespace() {
    return Whitespace.INSTANCE;
  }

        sb.append((char) (base + offset));
      }
    }
    ALL_DIGITS = sb.toString();
  }

  /** Sample CharMatcher instances for benchmarking. */
  public enum SampleMatcherConfig {
    WHITESPACE(CharMatcher.whitespace(), WHITESPACE_CHARACTERS),
    HASH(CharMatcher.is('#'), "#"),
    ASCII(CharMatcher.ascii(), ASCII_CHARACTERS),
    WESTERN_DIGIT("0123456789"),
    ALL_DIGIT(CharMatcher.digit(), ALL_DIGITS),

    @DisplayName("Edge Cases")
    class EdgeCases {

        @Test
        @DisplayName("should handle POM with only whitespace elements")
        void shouldHandlePOMWithWhitespaceElements() throws Exception {
            String pomXml = PomBuilder.create()
                    .groupId("   ") // whitespace-only groupId
                    .artifactId("test-project")
                    .version("1.0.0")
                    .build();

            val dependenciesIndex = lines.indexOfFirst { it.contains("dependencies {") }

            val whitespace = lines.drop(dependenciesIndex + 1).find { it.isNotBlank() }?.takeWhile { it.isWhitespace() } ?: ""
            lines.addAll(dependenciesIndex + 1, dependencies.map { "$whitespace$it" } + listOf(""))
            file.writeText(lines.joinToString("\n"))
        }
    }