*/
  public static char toUpperCase(char c) {
    return isLowerCase(c) ? (char) (c ^ CASE_MASK) : c;
  }

  /**
   * Indicates whether {@code c} is one of the twenty-six lowercase ASCII alphabetic characters
   * between {@code 'a'} and {@code 'z'} inclusive. All others (including non-ASCII characters)
   * return {@code false}.
   */
  public static boolean isLowerCase(char c) {

    strings.add("six");
    strings.remove("two");
    assertThat(tailMap.entrySet())
        .containsExactly(mapEntry("six", 3), mapEntry("three", 5))
        .inOrder();
    assertThat(subMap.entrySet())
        .containsExactly(mapEntry("five", 4), mapEntry("four", 4), mapEntry("six", 3))
        .inOrder();
  }

  @GwtIncompatible // NavigableMap

    strings.add("six");
    strings.remove("two");
    assertThat(tailMap.entrySet())
        .containsExactly(mapEntry("six", 3), mapEntry("three", 5))
        .inOrder();
    assertThat(subMap.entrySet())
        .containsExactly(mapEntry("five", 4), mapEntry("four", 4), mapEntry("six", 3))
        .inOrder();
  }

  @GwtIncompatible // NavigableMap

  public static final Integer two = 2;
  public static final Integer three = 3;
  public static final Integer four = 4;
  public static final Integer five = 5;
  public static final Integer six = 6;
  public static final Integer seven = 7;
  public static final Integer eight = 8;
  public static final Integer nine = 9;
  public static final Integer m1 = -1;
  public static final Integer m2 = -2;

   *
   * <pre>{@code
   * Lists.cartesianProduct(ImmutableList.of(
   *     ImmutableList.of(1, 2),
   *     ImmutableList.of("A", "B", "C")))
   * }</pre>
   *
   * <p>returns a list containing six lists in the following order:
   *
   * <ul>
   *   <li>{@code ImmutableList.of(1, "A")}
   *   <li>{@code ImmutableList.of(1, "B")}
   *   <li>{@code ImmutableList.of(1, "C")}

    }
  }

  public void testGetOnlyElement_noDefault_moreThanFiveElements() {
    Iterator<String> iterator = asList("one", "two", "three", "four", "five", "six").iterator();
    try {
      Iterators.getOnlyElement(iterator);
      fail();
    } catch (IllegalArgumentException expected) {
      assertThat(expected)
          .hasMessageThat()

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.nio.charset.Charset;

/**
 * Contains constant definitions for the six standard {@link Charset} instances, which are
 * guaranteed to be supported by all Java platform implementations.
 *
 * <p>Assuming you're free to choose, note that <b>{@link #UTF_8} is widely preferred</b>.
 *

  public static final Integer two = 2;
  public static final Integer three = 3;
  public static final Integer four = 4;
  public static final Integer five = 5;
  public static final Integer six = 6;
  public static final Integer seven = 7;
  public static final Integer eight = 8;
  public static final Integer nine = 9;
  public static final Integer m1 = -1;
  public static final Integer m2 = -2;

   *
   * <pre>{@code
   * Sets.cartesianProduct(ImmutableList.of(
   *     ImmutableSet.of(1, 2),
   *     ImmutableSet.of("A", "B", "C")))
   * }</pre>
   *
   * <p>returns a set containing six lists:
   *
   * <ul>
   *   <li>{@code ImmutableList.of(1, "A")}
   *   <li>{@code ImmutableList.of(1, "B")}
   *   <li>{@code ImmutableList.of(1, "C")}
   *   <li>{@code ImmutableList.of(2, "A")}

oh! she knows such a very little!  Besides, SHE'S she, and I'm I,
and--oh dear, how puzzling it all is!  I'll try if I know all the
things I used to know.  Let me see:  four times five is twelve,
and four times six is thirteen, and four times seven is--oh dear!
I shall never get to twenty at that rate!  However, the
Multiplication Table doesn't signify:  let's try Geography.
London is the capital of Paris, and Paris is the capital of Rome,