* absent, it will fall back to a heavyweight operation that will open a stream, read (or {@link
   * InputStream#skip(long) skip}, if possible) to the end of the stream and return the total number
   * of bytes that were read.
   *
   * <p>Note that for some sources that implement {@link #sizeIfKnown} to provide a more efficient
   * implementation, it is <i>possible</i> that this method will return a different number of bytes

import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with LargeTest.
 *
 * <p>Why use a custom annotation instead of {@code android.test.suitebuilder.annotation.Suppress}?
 * I'm not completely sure that this is the right choice, but it has various advantages:
 *

    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

        }
      }
    }
  }

  private void waitForInterrupt(Thread currentThread) {
    /*
     * If someone called cancel(true), it is possible that the interrupted bit hasn't been set yet.
     * Wait for the interrupting thread to set DONE. (See interruptTask().) We want to wait so that
     * the interrupting thread doesn't interrupt the _next_ thing to run on this thread.
     *

@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

  abstract Graph<Integer> createGraph();

  /**
   * A proxy method that adds the node {@code n} to the graph being tested. In case of Immutable
   * graph implementations, this method should replace {@link #graph} with a new graph that includes
   * this node.
   */
  abstract void addNode(Integer n);

  /**
   * A proxy method that adds the edge {@code e} to the graph being tested. In case of Immutable

      return null;
    }

    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj instanceof GoodEquals) {
        GoodEquals that = (GoodEquals) obj;
        return a.equals(that.a) && b == that.b;
      } else {
        return false;
      }
    }

    @Override
    public int hashCode() {
      return 0;
    }
  }

  static class BadEquals {

    }
  }

  /**
   * Verifies that a collection is immutable.
   *
   * <p>A collection is considered immutable if:
   *
   * <ol>
   *   <li>All its mutation methods result in UnsupportedOperationException, and do not change the
   *       underlying contents.
   *   <li>All methods that return objects that can indirectly mutate the collection throw