},
                        "tags": {
                            "title": "Tags",
                            "uniqueItems": True,
                            "type": "array",
                            "items": {"type": "string"},
                            "default": [],
                        },
                    },
                },
                "ValidationError": {

                                {
                                    "title": "X-Token",
                                    "anyOf": [
                                        {"type": "array", "items": {"type": "string"}},
                                        {"type": "null"},
                                    ],
                                }
                            )

                        },
                        "tax": {"title": "Tax", "type": "number", "default": 10.5},
                        "tags": {
                            "title": "Tags",
                            "type": "array",
                            "items": {"type": "string"},
                            "default": [],
                        },
                    },
                },
                "ValidationError": {

                            "required": False,
                            "schema": IsDict(
                                {
                                    "anyOf": [
                                        {"type": "array", "items": {"type": "string"}},
                                        {"type": "null"},
                                    ],
                                    "title": "Q",
                                }

ECL0010=argument[{0}] is null or empty string.
ECL0011=argument[{0}] is null or empty array.
ECL0012=argument[{0}] is null or empty collection.
ECL0013=argument[{0}] is null or empty map.
ECL0014=argument[{0}] which is null the index of array is negative integer.
ECL0015=argument[{0}] which is null the index of array exceed the size of array[{1}].
ECL0016=key[{0}] is not included in this BeanMap : {1}.
ECL0017=Exception occurred, because {0}

  public void testEquals_containingNullKey() {
    Collection<Entry<K, V>> entries = getSampleEntries(getNumEntries() - 1);
    entries.add(entry(null, v3()));

    resetContainer(getSubjectGenerator().create(entries.toArray()));
    assertTrue(
        "A Map should equal any other Map containing the same entries,"
            + " even if some keys are null.",
        getMap().equals(newHashMap(entries)));
  }

  public void testKeySet_nullToArray() {
    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Object> keys = cache.asMap().keySet();
      assertThrows(NullPointerException.class, () -> keys.toArray((Object[]) null));
      checkEmpty(cache);
    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {

  public void testKeySet_nullToArray() {
    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Object> keys = cache.asMap().keySet();
      assertThrows(NullPointerException.class, () -> keys.toArray((Object[]) null));
      checkEmpty(cache);
    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {

  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedNullPresent() {
    E[] array = createArrayWithNullElement();
    collection = getSubjectGenerator().create(array);
    assertFalse("add(nullPresent) should return false", getSet().add(null));
    expectContents(array);
  }

  /**
   * Returns the {@link Method} instance for {@link #testAdd_supportedNullPresent()} so that tests

                                "application/json": {
                                    "schema": {
                                        "title": "Response Items-Get Items",
                                        "type": "array",
                                        "items": {"$ref": "#/components/schemas/Item"},
                                    }
                                }
                            },
                        }