* well-tested. A purist would object to this, but what can I say, we're dirty cheaters.
     */
    map.put(Integer.class, new Integer(5));
    assertThrows(ClassCastException.class, () -> map.put(Double.class, new Long(42)));
    // Won't compile: map.put(String.class, "x");
  }

  public void testPutAndGetInstance() {
    assertNull(map.putInstance(Integer.class, new Integer(5)));

    return delegate.toArray();
  }

  @Override
  public <T> T[] toArray(T[] a) {
    return delegate.toArray(a);
  }

  @CanIgnoreReturnValue
  private <T> T checkValid(T t) {
    // a ClassCastException is what's supposed to happen!
    @SuppressWarnings("unchecked")
    E e = (E) t;
    int unused = comparator().compare(e, e);
    return t;
  }

  @Override

  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_wrongType() {
    try {
      assertFalse(collection.remove(WrongType.VALUE));
    } catch (ClassCastException tolerated) {
    }
    expectUnchanged();
  }

    try {
      assertFalse(
          "removeAll(containsWrongType) should return false or throw",
          collection.removeAll(MinimalCollection.of(WrongType.VALUE)));
    } catch (ClassCastException tolerated) {
    }
    expectUnchanged();
  }

    }
  }

  @SuppressWarnings("unchecked") // C can only be @Nullable Character or Character
  protected @NonNull C cellValue(Character character) {
    return (C) character;
  }

  // Only safe wrt. ClassCastException. Not null-safe (can be used to test expected Table NPEs)
  @SuppressWarnings("unchecked")
  protected C nullableCellValue(@Nullable Character character) {
    return (C) character;
  }

          if (candidate != null && candidate.getValue().upperBound.equals(cut)) {
            return candidate.getValue();
          }
        } catch (ClassCastException e) {
          return null;
        }
      }
      return null;
    }

    @Override
    Iterator<Entry<Cut<C>, Range<C>>> entryIterator() {
      /*

        SmbTreeImpl unwrapped = tree.unwrap(SmbTreeImpl.class);
        assertEquals(tree, unwrapped);
        // Test unwrapping to a non-assignable type should fail
        assertThrows(ClassCastException.class, () -> {
            // Create a mock class that extends SmbTree but is not assignable from SmbTreeImpl
            class CustomSmbTree extends SmbTreeImpl {
                CustomSmbTree() {

    try {
      assertFalse(
          "removeAll(containsWrongType) should return false or throw",
          collection.removeAll(MinimalCollection.of(WrongType.VALUE)));
    } catch (ClassCastException tolerated) {
    }
    expectUnchanged();
  }

        }

        @Override
        public <T extends Credentials> T unwrap(Class<T> type) {
            if (type.isInstance(this)) {
                return type.cast(this);
            }
            throw new ClassCastException("Cannot unwrap to " + type.getName());
        }
    }

    static class SelfRenewingCreds extends BaseCreds {
        @Override
        public CredentialsInternal renew() {

    }
  }

  @SuppressWarnings("unchecked") // C can only be @Nullable Character or Character
  protected @NonNull C cellValue(Character character) {
    return (C) character;
  }

  // Only safe wrt. ClassCastException. Not null-safe (can be used to test expected Table NPEs)
  @SuppressWarnings("unchecked")
  protected C nullableCellValue(@Nullable Character character) {
    return (C) character;
  }