# Tutorial - User Guide

This tutorial shows you how to use **FastAPI** with most of its features, step by step.

Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific API needs.

It is also built to work as a future reference so you can come back and see exactly what you need.

## Run the code

   */
  @Override
  Set<V> createCollection() {
    return Platform.<V>newHashSetWithExpectedSize(expectedValuesPerKey);
  }

  /**
   * @serialData expectedValuesPerKey, number of distinct keys, and then for each distinct key: the
   *     key, number of values for that key, and the key's values
   */
  @GwtIncompatible // java.io.ObjectOutputStream
  @J2ktIncompatible

    ]

    static void main(String[] commits) {
        println("Commits to check: ${Arrays.toString(commits)}")
        try {
            commits.each { checkCommit(it) }
        } finally {
            THREAD_POOL.shutdown()
        }
    }

    static void checkCommit(String commit) {
        List<String> parentCommits = parentCommitsOf(commit)

   * undocumented and subject to change.
   *
   * <p>Note that if {@code list} is a {@code List<String>}, then {@code ImmutableList.copyOf(list)}
   * returns an {@code ImmutableList<String>} containing each of the strings in {@code list}, while
   * {@code ImmutableList.of(list)} returns an {@code ImmutableList<List<String>>} containing one
   * element (the given list itself).
   *

   * Returns true if the edges in this network are directed. Directed edges connect a {@link
   * EndpointPair#source() source node} to a {@link EndpointPair#target() target node}, while
   * undirected edges connect a pair of nodes to each other.
   */
  boolean isDirected();

  /**
   * Returns true if this network allows parallel edges. Attempting to add a parallel edge to a

// AllocationResult contains attributes of an allocated resource.
message AllocationResult {
  // ResourceHandles contain the state associated with an allocation that
  // should be maintained throughout the lifetime of a claim. Each
  // ResourceHandle contains data that should be passed to a specific kubelet
  // plugin once it lands on a node. This data is returned by the driver
  // after a successful allocation and is opaque to Kubernetes. Driver

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

// Package etag provides an implementation of S3 ETags.
//
// Each S3 object has an associated ETag that can be
// used to e.g. quickly compare objects or check whether
// the content of an object has changed.
//
// In general, an S3 ETag is an MD5 checksum of the object

 *
 * <p>{@code ByteSource} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a stream:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the
 *       returned stream is closed.
 *   <li><b>Convenience methods:</b> These are implementations of common operations that are

   * by delaying the per-stack-frame work until each element is accessed. Roughly speaking:
   *
   * <ul>
   *   <li>{@code getStackTrace} takes {@code stackSize} time to return but then negligible time to
   *       retrieve each element of the returned list.
   *   <li>{@code lazyStackTrace} takes negligible time to return but then {@code 1/stackSize} time

         * The checksum extension SHOULD NOT contain dot (".") character.
         * Example: "sha1".
         */
        @Nonnull
        String getFileExtension();

        /**
         * Each invocation of this method returns a new instance of calculator, never {@code null} value.
         */
        @Nonnull
        ChecksumCalculator getCalculator();
    }

    /**
     * The checksum calculator.