assertEquals("FOO", UPPER_CAMEL.to(UPPER_UNDERSCORE, "Foo"));
    assertEquals("FOO_BAR", UPPER_CAMEL.to(UPPER_UNDERSCORE, "FooBar"));
    assertEquals("H_T_T_P", UPPER_CAMEL.to(UPPER_UNDERSCORE, "HTTP"));
    assertEquals("H__T__T__P", UPPER_CAMEL.to(UPPER_UNDERSCORE, "H_T_T_P"));
  }

  public void testUpperUnderscoreToLowerHyphen() {
    assertEquals("foo", UPPER_UNDERSCORE.to(LOWER_HYPHEN, "FOO"));

    assertEquals("FOO", UPPER_CAMEL.to(UPPER_UNDERSCORE, "Foo"));
    assertEquals("FOO_BAR", UPPER_CAMEL.to(UPPER_UNDERSCORE, "FooBar"));
    assertEquals("H_T_T_P", UPPER_CAMEL.to(UPPER_UNDERSCORE, "HTTP"));
    assertEquals("H__T__T__P", UPPER_CAMEL.to(UPPER_UNDERSCORE, "H_T_T_P"));
  }

  public void testUpperUnderscoreToLowerHyphen() {
    assertEquals("foo", UPPER_UNDERSCORE.to(LOWER_HYPHEN, "FOO"));

    assertEquals("training", Optional.of("training").get());
  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional
  public void testOr_T_present() {
    assertEquals("a", Optional.of("a").or("default"));
  }

  public void testOr_T_absent() {
    assertEquals("default", Optional.absent().or("default"));
  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional

    assertEquals("training", Optional.of("training").get());
  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional
  public void testOr_T_present() {
    assertEquals("a", Optional.of("a").or("default"));
  }

  public void testOr_T_absent() {
    assertEquals("default", Optional.absent().or("default"));
  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional

         * only way to get a TypeVariable instance for the resolved types is to create our own. The
         * created TypeVariable will not interoperate with any JDK TypeVariable. But this is OK: We
         * don't _want_ our new TypeVariable to be equal to the JDK TypeVariable because it has
         * _different bounds_ than the JDK TypeVariable. And it wouldn't make sense for our new

      return network.incidentNodes(edge);
    }

    @Override
    public Set<E> adjacentEdges(E edge) {
      return network.adjacentEdges(edge);
    }

    // _don't_ override edge*Connecting*; we want the behavior from AbstractNetwork
  }

  public void testNullPointers() {
    /*
     * Don't bother testing: Preconditions defines a bunch of methods that accept a template (or
     * even entire message) that simultaneously:
     *
     * - _shouldn't_ be null, so we don't annotate it with @Nullable
     *
     * - _can_ be null without causing a runtime failure (because we don't want the interesting

      return network.incidentNodes(edge);
    }

    @Override
    public Set<E> adjacentEdges(E edge) {
      return network.adjacentEdges(edge);
    }

    // _don't_ override edge*Connecting*; we want the behavior from AbstractNetwork
  }

  public void testNullPointers() {
    /*
     * Don't bother testing: Preconditions defines a bunch of methods that accept a template (or
     * even entire message) that simultaneously:
     *
     * - _shouldn't_ be null, so we don't annotate it with @Nullable
     *
     * - _can_ be null without causing a runtime failure (because we don't want the interesting