* limitations under the License.
 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES;

    void testEncodeZeroLength() {
        // Test encoding with zero length
        byte[] data = { 0x01, 0x02, 0x03 };
        ByteEncodable encodable = new ByteEncodable(data, 0, 0);
        byte[] dest = new byte[3];

        int encodedLen = encodable.encode(dest, 0);

        // Verify encoded length
        assertEquals(0, encodedLen, "Encoded length should be zero for zero length encodable");

    }
  }

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testGet_nonNullWhenNullContained() {
    initMapWithNullKey();
    assertNull("get(notPresent) should return null", get(k3()));
  }

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testGet_nullContained() {
    initMapWithNullKey();

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testFind_nonNullWhenNullContained() {
    initCollectionWithNullElement();
    assertEquals(getMethodName() + "(notPresent) should return -1", -1, find(e3()));
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testFind_nullContained() {
    initCollectionWithNullElement();

  @CollectionSize.Require(absent = ZERO)
  public void testSetValueNullUnsupported() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      assertThrows(NullPointerException.class, () -> entry.setValue(null));
      expectUnchanged();
    }
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testSetValueNullSupported() {

    }
  }

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testGet_nonNullWhenNullContained() {
    initMapWithNullKey();
    assertNull("get(notPresent) should return null", get(k3()));
  }

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testGet_nullContained() {
    initMapWithNullKey();

 * is {@code addAndGet(K, long)}, which adds a {@code long} to the value currently associated with
 * {@code K}. If a key has not yet been associated with a value, its implicit value is zero.
 *
 * <p>Most methods in this class treat absent values and zero values identically, as individually
 * documented. Exceptions to this are {@link #containsKey}, {@link #size}, {@link #isEmpty}, {@link
 * #asMap}, and {@link #toString}.
 *

 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES;

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_otherListContainingNull() {
    List<E> other = new ArrayList<>(getSampleElements());
    other.set(other.size() / 2, null);
    assertFalse(
        "Two Lists should not be equal if exactly one of them has null at a given index.",
        getList().equals(other));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)

  public Stats yStats() {
    return yStats;
  }

  /**
   * Returns the population covariance of the values. The count must be non-zero.
   *
   * <p>This is guaranteed to return zero if the dataset contains a single pair of finite values. It
   * is not guaranteed to return zero when the dataset consists of the same pair of values multiple
   * times, due to numerical errors.
   *
   * <h3>Non-finite values</h3>
   *