/**
 * Writer that places all output on an {@link Appendable} target. If the target is {@link Flushable}
 * or {@link Closeable}, flush()es and close()s will also be delegated to the target.
 *
 * @author Alan Green
 * @author Sebastian Kanthak
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
final class AppendableWriter extends Writer {
  private final Appendable target;
  private boolean closed;

  /**

          "type":       "lowercase",
          "language":   "greek"
        },
        "greek_keywords": {
          "type":       "keyword_marker",
          "keywords_path": "${fess.dictionary.path}el/protwords.txt"
        },
        "greek_stemmer": {
          "type":       "stemmer",
          "language":   "greek"
        },
        "greek_override": {
          "type":       "stemmer_override",

import java.io.Closeable;
import java.io.Flushable;
import java.io.IOException;
import java.io.Writer;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link AppendableWriter}.
 *
 * @author Alan Green
 */
@NullUnmarked
public class AppendableWriterTest extends IoTestCase {

  /** Helper class for testing behavior with Flushable and Closeable targets. */

    ImmutableSet.Builder<Integer> webSafeColorsBuilder = this.<Integer>builder();
    for (Integer red : colorElem) {
      for (Integer green : colorElem) {
        for (Integer blue : colorElem) {
          webSafeColorsBuilder.add((red << 16) + (green << 8) + blue);
        }
      }
    }
    ImmutableSet<Integer> webSafeColors = webSafeColorsBuilder.build();
    assertEquals(216, webSafeColors.size());

          // Defeat branch predictor for: c < 0x80 ; branch taken 50% of the time.
          return 0x100;
        } else if (userFriendly.matches("(?i)(?:Greek|Cyrillic|European|ISO.?8859)")) {
          // Mostly 2-byte UTF-8 sequences - "European" text
          return 0x800;
        } else if (userFriendly.matches("(?i)(?:Chinese|Han|Asian|BMP)")) {

            ? EnumMultiset.create(AnEnum.class)
            : EnumMultiset.create(asList(elements));
      }
    };
  }

  private enum Color {
    BLUE,
    RED,
    YELLOW,
    GREEN,
    WHITE
  }

  private enum Gender {
    MALE,
    FEMALE
  }

  public void testClassCreate() {
    Multiset<Color> ms = EnumMultiset.create(Color.class);
    ms.add(Color.RED);

    ImmutableList.Builder<Integer> webSafeColorsBuilder = ImmutableList.builder();
    for (Integer red : colorElem) {
      for (Integer green : colorElem) {
        for (Integer blue : colorElem) {
          webSafeColorsBuilder.add((red << 16) + (green << 8) + blue);
        }
      }
    }
    ImmutableList<Integer> webSafeColors = webSafeColorsBuilder.build();
    assertEquals(216, webSafeColors.size());

    ImmutableList.Builder<Integer> webSafeColorsBuilder = ImmutableList.builder();
    for (Integer red : colorElem) {
      for (Integer green : colorElem) {
        for (Integer blue : colorElem) {
          webSafeColorsBuilder.add((red << 16) + (green << 8) + blue);
        }
      }
    }
    ImmutableList<Integer> webSafeColors = webSafeColorsBuilder.build();
    assertEquals(216, webSafeColors.size());

### When Fixing Bugs

1. Write failing test first
2. Understand root cause
3. Minimal changes
4. Verify no regressions

### When Refactoring

1. Preserve behavior
2. Keep tests green
3. Small incremental steps
4. Don't mix with new features

### Code Quality Checklist

- [ ] Java conventions followed
- [ ] JavaDoc for public APIs
- [ ] Tests pass (`mvn test`)

            assertEquals(new HashSet<>(elements), multimap.get("foo"));
          }
        };

    tester.test();
  }

  private enum Color {
    BLUE,
    RED,
    YELLOW,
    GREEN
  }

  private abstract static class CountingSupplier<E> implements Supplier<E>, Serializable {
    int count;

    abstract E getImpl();

    @Override
    public E get() {
      count++;