* which has a method {@code getParents()} that retrieves its predecessors in a graph:
 *
 * {@snippet :
 * someGraphAlgorithm(startNode, MyNode::getParents);
 * }
 *
 * <p>If you have some other mechanism for returning the predecessors of a node, or one that doesn't
 * return a {@code Iterable<? extends N>}, then you can use a lambda to perform a more general
 * transformation:
 *
 * {@snippet :

        MapTestSuiteBuilder.using(
                new TestTypeToInstanceMapGenerator() {
                  // Other tests will verify what real, warning-free usage looks like
                  // but here we have to do some serious fudging
                  @Override
                  @SuppressWarnings({"unchecked", "rawtypes"})
                  public Map<TypeToken, Object> create(Object... elements) {

# This file specifies the Linux OS versions on which we can't build and
# test Docker images for some reason. These values correspond to ID and
# VERSION_ID from /etc/os-release, and a matching value will cause the
# Docker tests to be skipped on that OS. If /etc/os-release doesn't exist
# (as is the case on centos-6, for example) then that OS will again be
# excluded.
debian-8
opensuse-leap-15.1
ol-7.7
sles-12.3 # older version used in Vagrant image
sles-12.5

## Features

The extractor should handle:

- YAML front matter extraction
- Heading structure
- **Bold text** and *italic text*
- Lists and other formatting

### Code Examples

Here is some inline `code` and a code block:

```java
public class Example {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}
```

## Links

   * @see IntStream#findFirst()
   * @throws NullPointerException if the last element of the stream is null
   */
  public static OptionalInt findLast(IntStream stream) {
    // findLast(Stream) does some allocation, so we might as well box some more
    java.util.Optional<Integer> boxedLast = findLast(stream.boxed());
    return boxedLast.map(OptionalInt::of).orElse(OptionalInt.empty());
  }

  /**

    assertThat(cache.asMap().computeIfPresent(key, (k, v) -> "2")).isEqualTo("2");
  }

  public void testUpdates() {
    cache.put(key, "1");
    // simultaneous update for same key, some null, some non-null
    doParallelCacheOp(
        count,
        n -> {
          cache.asMap().compute(key, (k, v) -> n % 2 == 0 ? v + delimiter + n : null);
        });
    assertThat(cache.size()).isAtMost(1);
  }

   * opening the data stream.
   *
   * <p>The default implementation returns {@link Optional#absent}. Some sources, such as a file,
   * may return a non-absent value. Note that in such cases, it is <i>possible</i> that this method
   * will return a different number of bytes than would be returned by reading all of the bytes (for
   * example, some special files may return a size of 0 despite actually having content when read).
   *

 *
 * <p>While it is recommended that service lifecycles be managed via this class, state transitions
 * initiated via other mechanisms do not impact the correctness of its methods. For example, if the
 * services are started by some mechanism besides {@link #startAsync}, the listeners will be invoked
 * when appropriate and {@link #awaitHealthy} will still work as expected.
 *

 *
 * <p>While it is recommended that service lifecycles be managed via this class, state transitions
 * initiated via other mechanisms do not impact the correctness of its methods. For example, if the
 * services are started by some mechanism besides {@link #startAsync}, the listeners will be invoked
 * when appropriate and {@link #awaitHealthy} will still work as expected.
 *

   * -XX:+ExplicitGCInvokesConcurrent} is used.
   *
   * <p>Whenever possible, it is preferable to test directly for some observable change resulting
   * from GC, as with {@link #awaitClear}. Because there are no guarantees for the order of GC
   * finalization processing, there may still be some unfinished work for the GC to do after this
   * method returns.
   *