return nullptr;
#else
  TF_Library* lib_handle = new TF_Library;
  static tensorflow::mutex mu(tensorflow::LINKER_INITIALIZED);
  static std::unordered_map<std::string, void*>* loaded_libs =
      new std::unordered_map<std::string, void*>();
  tensorflow::Env* env = tensorflow::Env::Default();
  {
    tensorflow::mutex_lock lock(mu);
    auto it = loaded_libs->find(library_filename);

at least one of which is non-synchronizing,
which are unordered by happens before
(that is, neither <i>r</i> happens before <i>w</i>
nor <i>w</i> happens before <i>r</i>).
</p>

<p>
A <i>write-write data race</i> on memory location <i>x</i>
consists of two write-like memory operations <i>w</i> and <i>w'</i> on <i>x</i>,
at least one of which is non-synchronizing,
which are unordered by happens before.
</p>

<p>

  std::vector<int64_t> source_tensor_ids = MakeTensorIDList(sources);
  tensorflow::gtl::FlatSet<int64_t> sources_set(source_tensor_ids.begin(),
                                                source_tensor_ids.end());
  std::unordered_map<int64_t, TapeTensor> sources_that_are_targets;
  for (int i = 0; i < target_tensor_ids.size(); ++i) {
    int64_t target_id = target_tensor_ids[i];
    if (sources_set.find(target_id) != sources_set.end()) {

                OverConstrainedVersionException.class, () -> collect(createSet(new Object[] {a.artifact})));
        assertTrue(e.getMessage().contains("[3.2.1-v3235e, 3.3.0-v3346]"), "Versions unordered");
        assertTrue(e.getMessage().contains("Path to dependency:"), "DependencyTrail unresolved");
    }

    private Artifact getArtifact(String id, Set artifacts) {
        for (Object artifact : artifacts) {

    void checkAcquiredLock(Policy policy, LockGraphNode acquiredLock) {
      // checkAcquiredLock() should never be invoked by a lock that has already
      // been acquired. For unordered locks, aboutToAcquire() ensures this by
      // checking isAcquiredByCurrentThread(). For ordered locks, however, this
      // can happen because multiple locks may share the same LockGraphNode. In
      // this situation, throw an IllegalStateException as defined by contract

    }
    return HashCode.fromBytesNoCopy(resultBytes);
  }

  /**
   * Returns a hash code, having the same bit length as each of the input hash codes, that combines
   * the information of these hash codes in an unordered fashion. That is, whenever two equal hash
   * codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
   * was computed from the <i>same</i> input hash codes in <i>some</i> order.
   *

    this.spliteratorSuppliers = checkNotNull(spliteratorSuppliers);
  }

  @SafeVarargs
  @CanIgnoreReturnValue
  public final Ordered expect(Object... elements) {
    return expect(Arrays.asList(elements));
  }

  @CanIgnoreReturnValue
  public final Ordered expect(Iterable<?> elements) {
    List<List<E>> resultsForAllStrategies = new ArrayList<>();

     *     be arbitrarily reordered by this method call
     * @return an unmodifiable, ordered map of results: the keys will be the specified quantile
     *     indexes, and the values the corresponding quantile values. When iterating, entries in the
     *     map are ordered by quantile index in the same order that the indexes were passed to the
     *     {@code indexes} method.

  }

  public void testCellSetToString_ordered() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals(
        "[(foo,1)=a, (foo,2)=null, (foo,3)=c, "
            + "(bar,1)=b, (bar,2)=null, (bar,3)=null, "
            + "(cat,1)=null, (cat,2)=null, (cat,3)=null]",
        table.cellSet().toString());
  }

  public void testRowKeySetToString_ordered() {

  }

  public void testCellSetToString_ordered() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals(
        "[(foo,1)=a, (foo,2)=null, (foo,3)=c, "
            + "(bar,1)=b, (bar,2)=null, (bar,3)=null, "
            + "(cat,1)=null, (cat,2)=null, (cat,3)=null]",
        table.cellSet().toString());
  }

  public void testRowKeySetToString_ordered() {