if (pomFiles == null) {
                    pomFiles = new ArrayList<>(Arrays.asList(collision.getFile(), project.getFile()));
                    collisions.put(projectId, pomFiles);
                } else {
                    pomFiles.add(project.getFile());
                }
            }
        }

        if (!collisions.isEmpty()) {

            oneWay = OneWayCryptographer.createSha512Cryptographer();
        } else if ("md5".equalsIgnoreCase(digestAlgorithm)) {
            logger.warn("MD5 digest is deprecated due to its collision vulnerabilities. Please consider migrating to SHA-256. algorithm={}",
                    digestAlgorithm);
            oneWay = new OneWayCryptographer("MD5", OneWayCryptographer.ENCODING_UTF8);
        } else {

    assertThat(segment.get(key, hash)).isEqualTo(value);
    assertTrue(segment.containsKey(key, hash));
    assertTrue(segment.containsValue(value));
    assertFalse(segment.containsValue(nullValue));

    // hash collision
    InternalEntry<Object, Object, ?> dummyEntry =
        segment.newEntryForTesting(new Object(), hash, entry);
    Object dummyValue = new Object();
    WeakValueReference<Object, Object, ?> dummyValueRef =

    assertThat(segment.get(key, hash)).isEqualTo(value);
    assertTrue(segment.containsKey(key, hash));
    assertTrue(segment.containsValue(value));
    assertFalse(segment.containsValue(nullValue));

    // hash collision
    InternalEntry<Object, Object, ?> dummyEntry =
        segment.newEntryForTesting(new Object(), hash, entry);
    Object dummyValue = new Object();
    WeakValueReference<Object, Object, ?> dummyValueRef =

      SortedMap<K, V> map, Entry<? extends K, ? extends V> entry) {
    K key = checkNotNull(entry.getKey());
    V value = checkNotNull(entry.getValue());
    if (map.containsKey(key)) {
      // When a collision happens, the colliding entry is the first entry
      // of the tail map.
      Entry<K, V> previousEntry = map.tailMap(key).entrySet().iterator().next();
      throw new IllegalArgumentException(

        // probably intended. So no point in using an equal-but-different factory argument.
        // We check twice to avoid confusion caused by accidental hash collision.
        equalArgs.set(i, shouldBeEqualArg);
      }
    }
    return equalArgs;
  }

  private static boolean hashCodeInsensitiveToArgReference(

      int leftCode = identityHashCode(left);
      int rightCode = identityHashCode(right);
      if (leftCode != rightCode) {
        return leftCode < rightCode ? -1 : 1;
      }

      // identityHashCode collision (rare, but not as rare as you'd think)
      int result = getUid(left).compareTo(getUid(right));
      if (result == 0) {
        throw new AssertionError(); // extremely, extremely unlikely.
      }

    assertThat(segment.containsKey(key, hash)).isTrue();
    assertThat(segment.containsValue(value)).isTrue();
    assertThat(segment.containsValue(nullValue)).isFalse();

    // hash collision
    DummyEntry<Object, Object> dummy = DummyEntry.create(new Object(), hash, entry);
    Object dummyValue = new Object();
    ValueReference<Object, Object> dummyValueRef = map.newValueReference(dummy, dummyValue, 1);

    assertThat(segment.containsKey(key, hash)).isTrue();
    assertThat(segment.containsValue(value)).isTrue();
    assertThat(segment.containsValue(nullValue)).isFalse();

    // hash collision
    DummyEntry<Object, Object> dummy = DummyEntry.create(new Object(), hash, entry);
    Object dummyValue = new Object();
    ValueReference<Object, Object> dummyValueRef = map.newValueReference(dummy, dummyValue, 1);

      int leftCode = identityHashCode(left);
      int rightCode = identityHashCode(right);
      if (leftCode != rightCode) {
        return leftCode < rightCode ? -1 : 1;
      }

      // identityHashCode collision (rare, but not as rare as you'd think)
      int result = getUid(left).compareTo(getUid(right));
      if (result == 0) {
        throw new AssertionError(); // extremely, extremely unlikely.
      }