import static org.junit.Assert.assertThrows;
import static org.junit.Assert.fail;

import com.google.common.collect.ImmutableSet;
import com.google.common.testing.EqualsTester;
import java.util.Optional;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;
import org.junit.After;
import org.junit.Test;

/**
 * Abstract base class for testing undirected {@link Network} implementations defined in this

import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import org.apache.maven.api.DependencyScope;
import org.apache.maven.api.Lifecycle;

    public FileInputStream openStream() throws IOException {
      return new FileInputStream(file);
    }

    @Override
    public Optional<Long> sizeIfKnown() {
      if (file.isFile()) {
        return Optional.of(file.length());
      } else {
        return Optional.absent();
      }
    }

    @Override
    public long size() throws IOException {
      if (!file.isFile()) {

* Bridging with Kotlin code is polluted with platform types
* Some public APIs have incorrect nullability annotations (both overly restrictive and overly permissive)

While there are competing ways to represent absence (`Optional`, "Null Object" pattern, method overloads),
it is unlikely that we'll be able to remove `null` entirely.

After migrating to Java 8, we can use pluggable type checkers to ensure that our annotations are consistent, 

                    }
                    boolean optional = false;
                    if (!selector.isEmpty() && selector.charAt(0) == '?') {
                        optional = true;
                        selector = selector.substring(1);
                    }
                    projectActivation.addProjectActivation(selector, active, optional);
                }
            }
        }
    }

| com.squareup.okhttp3:mockwebserver3-junit4:5.0.0 | mockwebserver3.junit4 | Optional JUnit 4 integration.     |
| com.squareup.okhttp3:mockwebserver3-junit5:5.0.0 | mockwebserver3.junit5 | Optional JUnit 5 integration.     |
| com.squareup.okhttp3:mockwebserver:5.0.0         | okhttp3.mockwebserver | Obsolete. Depends on JUnit 4.     |

      result.add(Header(TARGET_PATH, RequestLine.requestPath(request.url)))
      val host = request.header("Host")
      if (host != null) {
        result.add(Header(TARGET_AUTHORITY, host)) // Optional.
      }
      result.add(Header(TARGET_SCHEME, request.url.scheme))

      for (i in 0 until headers.size) {
        // header names must be lowercase.
        val name = headers.name(i).lowercase(Locale.US)

   * </ul>
   *
   * @throws IllegalArgumentException if the specifier is not valid.
   */
  public static HostSpecifier fromValid(String specifier) {
    // Verify that no port was specified, and strip optional brackets from
    // IPv6 literals.
    HostAndPort parsedHost = HostAndPort.fromString(specifier);
    Preconditions.checkArgument(!parsedHost.hasPort());
    String host = parsedHost.getHost();

    }

    @Test
    void getOptionalProjectsBySelectorsReturnsMatches() {
        final HashSet<String> selectors = new HashSet<>();
        selectors.add(":maven-core");
        selectors.add(":optional");

        final MavenProject mavenProject = createMavenProject("maven-core");
        final List<MavenProject> listOfProjects = Collections.singletonList(mavenProject);

You could also use it to generate code automatically, for clients that communicate with your API. For example, frontend, mobile or IoT applications.

### Deploy your app (optional) { #deploy-your-app-optional }

You can optionally deploy your FastAPI app to <a href="https://fastapicloud.com" class="external-link" target="_blank">FastAPI Cloud</a>, go and join the waiting list if you haven't. 🚀