assertThat(e.getMessage()).contains(ERROR_REUSE_EDGE);
  }

  @Test
  public void addEdge_parallelSelfLoopEdge_notAllowed() {
    assume().that(graphIsMutable()).isTrue();
    assume().that(network.allowsSelfLoops()).isTrue();
    assume().that(network.allowsParallelEdges()).isFalse();

    addEdge(N1, N1, E11);
    IllegalArgumentException e =
        assertThrows(

    assume().that(graphIsMutable()).isTrue();
    assume().that(graph.allowsSelfLoops()).isTrue();

    graphAsMutableGraph.putEdge(N1, N1);
    assertThat(graphAsMutableGraph.putEdge(N1, N1)).isFalse();
  }

  @Test
  public void removeEdge_antiparallelEdges() {
    assume().that(graphIsMutable()).isTrue();

    putEdge(N1, N2);
    putEdge(N2, N1);

   * no such references and the tests here check that that trouble has not been in vain.
   *
   * When we reference FinalizableReferenceQueue in this test, we are referencing a class that is
   * loaded by this test and that will obviously remain loaded for as long as the test is running.
   * So in order to check ClassLoader garbage collection we need to create a new ClassLoader and

You could create an API with a *path operation* that could trigger a request to an *external API* created by someone else (probably the same developer that would be *using* your API).

The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

@GwtCompatible
@ElementTypesAreNonnullByDefault
final class NullnessCasts {
  /**
   * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that
   * that conversion is safe.
   *
   * <p>This method is intended to help with usages of type parameters that have {@linkplain
   * ParametricNullness parametric nullness}. If a type parameter instead ranges over only non-null

Our General Public Licenses are designed to make sure that you have the
freedom to distribute copies of free software (and charge for this
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To protect your rights, we need to make restrictions that forbid anyone

  // "Queue" means that requests that can not be executed upon arrival
  // are held in a queue until they can be executed or a queuing limit
  // is reached.
  // "Reject" means that requests that can not be executed upon arrival
  // are rejected.
  // Required.
  // +unionDiscriminator
  optional string type = 1;

  // `queuing` holds the configuration parameters for queuing.

  // "Queue" means that requests that can not be executed upon arrival
  // are held in a queue until they can be executed or a queuing limit
  // is reached.
  // "Reject" means that requests that can not be executed upon arrival
  // are rejected.
  // Required.
  // +unionDiscriminator
  optional string type = 1;

  // `queuing` holds the configuration parameters for queuing.

@GwtCompatible
@ElementTypesAreNonnullByDefault
final class NullnessCasts {
  /**
   * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that
   * that conversion is safe.
   *
   * <p>This method is intended to help with usages of type parameters that have {@linkplain
   * ParametricNullness parametric nullness}. If a type parameter instead ranges over only non-null

      "Licensor" shall mean the copyright owner or entity authorized by
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      "Legal Entity" shall mean the union of the acting entity and all
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