return new Joiner(separator);
  }

  /** Returns a joiner which automatically places {@code separator} between consecutive elements. */
  public static Joiner on(char separator) {
    return new Joiner(String.valueOf(separator));
  }

  private final String separator;

  private Joiner(String separator) {
    this.separator = checkNotNull(separator);
  }

  private Joiner(Joiner prototype) {

    return new Joiner(separator);
  }

  /** Returns a joiner which automatically places {@code separator} between consecutive elements. */
  public static Joiner on(char separator) {
    return new Joiner(String.valueOf(separator));
  }

  private final String separator;

  private Joiner(String separator) {
    this.separator = checkNotNull(separator);
  }

  private Joiner(Joiner prototype) {

 *
 * @author Ben Yu
 */
@ElementTypesAreNonnullByDefault
final class Types {

  /** Class#toString without the "class " and "interface " prefixes */
  private static final Joiner COMMA_JOINER = Joiner.on(", ").useForNull("null");

  /** Returns the array type of {@code componentType}. */
  static Type newArrayType(Type componentType) {
    if (componentType instanceof WildcardType) {

  }

  private static final Joiner joiner = Joiner.on(", ");

  @Override
  protected void assertMoreInvariants(Map<K, V> map) {
    // TODO: can these be moved to MapInterfaceTest?
    for (Entry<K, V> entry : map.entrySet()) {
      assertEquals(entry.getKey() + "=" + entry.getValue(), entry.toString());
    }

    assertEquals("{" + joiner.join(map.entrySet()) + "}", map.toString());

    return Types.newArrayType(resolvedComponentType);
  }

  private ParameterizedType resolveParameterizedType(ParameterizedType type) {
    Type owner = type.getOwnerType();
    Type resolvedOwner = (owner == null) ? null : resolveType(owner);
    Type resolvedRawType = resolveType(type.getRawType());

    Type[] args = type.getActualTypeArguments();
    Type[] resolvedArgs = resolveTypes(args);

        builder.add(field);
      }
    }
    return builder.build();
  }

  private static final Splitter SPLITTER = Splitter.on('_');
  private static final Joiner JOINER = Joiner.on('-');

  private static String upperToHttpHeaderName(
      String constantName,
      ImmutableBiMap<String, String> specialCases,
      ImmutableSet<String> uppercaseAcronyms) {

        builder.add(field);
      }
    }
    return builder.build();
  }

  private static final Splitter SPLITTER = Splitter.on('_');
  private static final Joiner JOINER = Joiner.on('-');

  private static String upperToHttpHeaderName(
      String constantName,
      ImmutableBiMap<String, String> specialCases,
      ImmutableSet<String> uppercaseAcronyms) {

  }

  private static void checkNoOutput(Joiner joiner, Iterable<Integer> set) {
    assertEquals("", joiner.join(set));
    assertEquals("", joiner.join(set.iterator()));

    Object[] array = Lists.newArrayList(set).toArray(new Integer[0]);
    assertEquals("", joiner.join(array));

    StringBuilder sb1FromIterable = new StringBuilder();
    assertSame(sb1FromIterable, joiner.appendTo(sb1FromIterable, set));

  }

  private static final Joiner joiner = Joiner.on(", ");

  @Override
  protected void assertMoreInvariants(Map<K, V> map) {
    // TODO: can these be moved to MapInterfaceTest?
    for (Entry<K, V> entry : map.entrySet()) {
      assertEquals(entry.getKey() + "=" + entry.getValue(), entry.toString());
    }

    assertEquals("{" + joiner.join(map.entrySet()) + "}", map.toString());

import java.util.Iterator;

/**
 * Benchmarks {@link Joiner} against some common implementations of delimiter-based string joining.
 *
 * @author Adomas Paltanavicius
 */
public class JoinerBenchmark {

  private static final String DELIMITER_STRING = ",";
  private static final char DELIMITER_CHARACTER = ',';

  private static final Joiner JOINER_ON_STRING = Joiner.on(DELIMITER_STRING);