public static Builder newBuilder() {
    return new Builder();
  }
@Test void builder_illegal() {
    EntrySplitter.Builder builder = EntrySplitter.newBuilder();

    assertThatThrownBy(() -> builder.maxEntries(-1))
      .isInstanceOf(IllegalArgumentException.class)
      .hasMessage("maxEntries <= 0");
    assertThatThrownBy(() -> builder.maxEntries(0))
      .isInstanceOf(IllegalArgumentException.class)
      .hasMessage("maxEntries <= 0");

    assertThatThrownBy(() -> builder.entrySeparator((char) 0))
      .isInstanceOf(IllegalArgumentException.class)
      .hasMessage("entrySeparator == 0");

    assertThatThrownBy(() -> builder.keyValueSeparator((char) 0))
      .isInstanceOf(IllegalArgumentException.class)
      .hasMessage("keyValueSeparator == 0");

    builder.keyValueSeparator(';').entrySeparator(';');
    assertThatThrownBy(builder::build)
      .isInstanceOf(IllegalArgumentException.class)
      .hasMessage("entrySeparator == keyValueSeparator");
  }