private static final Splitter COMMA_SPLITTER = Splitter.on(',');

  public void testSplitNullString() {
    try {
      COMMA_SPLITTER.split(null);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testCharacterSimpleSplit() {
    String simple = "a,b,c";
    Iterable<String> letters = COMMA_SPLITTER.split(simple);

  private static final Splitter COMMA_SPLITTER = Splitter.on(',');

  public void testSplitNullString() {
    try {
      COMMA_SPLITTER.split(null);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testCharacterSimpleSplit() {
    String simple = "a,b,c";
    Iterable<String> letters = COMMA_SPLITTER.split(simple);

 *
 * <p>{@code CacheBuilderSpec} supports parsing configuration off of a string, which makes it
 * especially useful for command-line configuration of a {@code CacheBuilder}.
 *
 * <p>The string syntax is a series of comma-separated keys or key-value pairs, each corresponding
 * to a {@code CacheBuilder} method.
 *
 * <ul>
 *   <li>{@code concurrencyLevel=[integer]}: sets {@link CacheBuilder#concurrencyLevel}.

 *
 * @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) {

 *
 * <p>{@code CacheBuilderSpec} supports parsing configuration off of a string, which makes it
 * especially useful for command-line configuration of a {@code CacheBuilder}.
 *
 * <p>The string syntax is a series of comma-separated keys or key-value pairs, each corresponding
 * to a {@code CacheBuilder} method.
 *
 * <ul>
 *   <li>{@code concurrencyLevel=[integer]}: sets {@link CacheBuilder#concurrencyLevel}.