### Ler um Único Hero

Podemos **ler** um único `Hero`.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[58:63] hl[60] *}

### Deletar um Hero

Também podemos **deletar** um `Hero`.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[66:73] hl[71] *}

### Executar o App

Você pode executar o app:

<div class="termy">

```console

  /** Test an empty collection. */
  ZERO(0),
  /** Test a one-element collection. */
  ONE(1),
  /** Test a three-element collection. */
  SEVERAL(3),
  /*
   * TODO: add VERY_LARGE, noting that we currently assume that the fourth
   * sample element is not in any collection
   */

  ANY(ZERO, ONE, SEVERAL);

  private final Set<Feature<? super Collection>> implied;

   * creation and removal (including automatic removal of zeroes). If the modification of an
   * AtomicInteger results in zero, we compareAndSet the value to zero; if that succeeds, we remove
   * the entry from the Map. If another operation sees a zero in the map, it knows that the entry is
   * about to be removed, so this operation may remove it (often by replacing it with a new
   * AtomicInteger).
   */

  /**
   * Returns the <a href="http://en.wikipedia.org/wiki/Variance#Population_variance">population
   * variance</a> of the values. The count must be non-zero.
   *
   * <p>This is guaranteed to return zero if the dataset contains only exactly one finite value. It
   * is not guaranteed to return zero when the dataset consists of the same value multiple times,
   * due to numerical errors. However, it is guaranteed never to return a negative result.
   *

                return emptyMap();
              }
            })
        .named("emptyMap")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)
        .suppressing(suppressForEmptyMap())
        .createTestSuite();
  }

  public Test testsForEmptyNavigableMap() {
    return MapTestSuiteBuilder.using(
            new TestStringSortedMapGenerator() {

            return BIGINTEGER_ITEM;
        }

        @Override
        public boolean isNull() {
            return BigInteger.ZERO.equals(value);
        }

        @Override
        public int compareTo(Item item) {
            if (item == null) {
                return BigInteger.ZERO.equals(value) ? 0 : 1; // 1.0 == 1, 1.1 > 1
            }

            switch (item.getType()) {
                case INT_ITEM:

 *       APIs are offered that don't).
 *   <li>Can't be passed directly to methods that expect {@code long[]} (though the most common
 *       utilities do have replacements here).
 *   <li>Dependency on {@code com.google.common} / Guava.
 * </ul>
 *
 * <p>Advantages compared to {@link com.google.common.collect.ImmutableList ImmutableList}{@code
 * <Long>}:
 *
 * <ul>

 *       APIs are offered that don't).
 *   <li>Can't be passed directly to methods that expect {@code int[]} (though the most common
 *       utilities do have replacements here).
 *   <li>Dependency on {@code com.google.common} / Guava.
 * </ul>
 *
 * <p>Advantages compared to {@link com.google.common.collect.ImmutableList ImmutableList}{@code
 * <Integer>}:
 *
 * <ul>

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeySupported() {
    initMapWithNullKey();
    expectContents(createArrayWithNullKey());
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyUnsupported() {

  @CollectionSize.Require(absent = ZERO)
  public void testSubList_subListRemoveAffectsOriginal() {
    List<E> subList = getList().subList(0, 1);
    subList.remove(0);
    List<E> expected = asList(createSamplesArray()).subList(1, getNumElements());
    expectContents(expected);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)