# ADR-0008 - Use NullAway for null checking

## Date

2025-08-06

## Context

Our codebase uses `null` extensively to represent an absence of value or optionality of the argument.
We utilize nullness annotations in Java code and somewhat rely on IDE warnings to guide us.
However, the Java code we have is not fully annotated, which causes several consequences:
* IDE warnings can be misleading

    modifications of Covered Software, or (ii) the combination of its
    Contributions with other software (except as part of its Contributor
    Version); or

(c) under Patent Claims infringed by Covered Software in the absence of
    its Contributions.

This License does not grant any rights in the trademarks, service marks,
or logos of any Contributor (except as may be necessary to comply with
the notice requirements in Section 3.4).

 * operations.
 *
 * <p>Certain cache configurations will result in the accrual of periodic maintenance tasks which
 * will be performed during write operations, or during occasional read operations in the absence of
 * writes. The {@link Cache#cleanUp} method of the returned cache will also perform maintenance, but
 * calling it should not be necessary with a high throughput cache. Only caches built with {@link

        .method("POST", requestBody1)
        .build()
    val response1 = client.newCall(request1).execute()
    assertThat(response1.code).isEqualTo(200)

    // Call 2: check for the absence of a deadline on the request body.
    val requestBody2: RequestBody =
      object : RequestBody() {
        override fun contentType(): MediaType = "text/plain".toMediaType()

 * operations.
 *
 * <p>Certain cache configurations will result in the accrual of periodic maintenance tasks which
 * will be performed during write operations, or during occasional read operations in the absence of
 * writes. The {@link Cache#cleanUp} method of the returned cache will also perform maintenance, but
 * calling it should not be necessary with a high throughput cache. Only caches built with {@link

  }

  public void testTransform_absent() {
    assertEquals(Optional.absent(), Optional.absent().transform(Functions.identity()));
    assertEquals(Optional.absent(), Optional.absent().transform(Functions.toStringFunction()));
  }

  public void testTransform_presentIdentity() {
    assertEquals(Optional.of("a"), Optional.of("a").transform(Functions.identity()));
  }

    nextInBucketVToK[src] = ABSENT;
  }

  @Override
  public void clear() {
    Arrays.fill(keys, 0, size, null);
    Arrays.fill(values, 0, size, null);
    Arrays.fill(hashTableKToV, ABSENT);
    Arrays.fill(hashTableVToK, ABSENT);
    Arrays.fill(nextInBucketKToV, 0, size, ABSENT);
    Arrays.fill(nextInBucketVToK, 0, size, ABSENT);
    Arrays.fill(prevInInsertionOrder, 0, size, ABSENT);

  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_VALUES)
  public void testContainsEntryWithNullValuePresent() {
    initMapWithNullValue();
    assertTrue(getMap().entrySet().contains(mapEntry(getKeyForNullValue(), null)));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testSetValue() {

  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_VALUES)
  public void testContainsEntryWithNullValuePresent() {
    initMapWithNullValue();
    assertTrue(getMap().entrySet().contains(mapEntry(getKeyForNullValue(), null)));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testSetValue() {

     *
     * @param all the --all option value (null for absent)
     * @param infer the --infer option value (null for absent)
     * @param model the --model option value (null for absent)
     * @param plugins the --plugins option value (null for absent)
     * @param modelVersion the --model-version option value (null for absent)
     * @return configured upgrade options
     */