Each file in that directory contains a list of features that may be added
to the next release of Go. The files in this directory only affect the
warning output from the go api tool. Each file should be named
nnnnn.txt, after the issue number for the accepted proposal.
(The #nnnnn suffix must also appear at the end of each line in the file;
that will be preserved when next/*.txt is concatenated into go1.XX.txt.)

  /**
   * Creates a new key that is not expected to be found in {@link #makePopulatedMap()}.
   *
   * @return a key.
   * @throws UnsupportedOperationException if it's not possible to make a key that will not be found
   *     in the map.
   */
  protected abstract K getKeyNotInPopulatedMap() throws UnsupportedOperationException;

  /**
   * Creates a new value that is not expected to be found in {@link #makePopulatedMap()}.

---

"_Honestly, what you've built looks super solid and polished. In many ways, it's what I wanted **Hug** to be - it's really inspiring to see someone build that._"

    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(

    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(

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

  <exclude name="**/testing/**"/>
</source>

<!--
    We used to set this only for packages that had manual supersource. That
    worked everywhere that I know of except for one place: when running the GWT
    util.concurrent tests under Guava.

    The problem is that GWT responds poorly to two .gwt.xml files in the same
    Java package; see

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

    IllegalArgumentException e =
        assertThrows(IllegalArgumentException.class, () -> putEdge(N1, N1));
    assertThat(e).hasMessageThat().contains(ERROR_SELF_LOOP);
  }

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