Each file is a list of API features, one per line.

go1.txt (and similarly named files) are frozen once a version has been
shipped. Each file adds new lines but does not remove any.

except.txt lists features that may disappear without breaking true
compatibility.

Starting with go1.19.txt, each API feature line must end in "#nnnnn"
giving the GitHub issue number of the proposal issue that accepted

# Install 7-Zip.
RUN (New-Object Net.WebClient).DownloadFile('https://www.7-zip.org/a/7z2201-x64.msi', '7z.msi'); \
    Start-Process msiexec.exe -ArgumentList \"/i 7z.msi /qn /norestart /log C:\\TEMP\\7z_install_log.txt\" -wait; \
    Remove-Item .\7z.msi;

# Download the Visual Studio 2022 Installer.
RUN (New-Object Net.WebClient).DownloadFile('https://aka.ms/vs/17/release/vs_community.exe', 'C:\TEMP\vs_community.exe');

    Multimap<String, Integer> map = create();
    map.put("bar", 1);
    map.put("foo", 2);
    map.put("bar", 3);
    map.put("bar", 4);
    assertEquals("[bar, foo]", map.keySet().toString());
    map.keySet().remove("bar");
    assertEquals("{foo=[2]}", map.toString());
  }

  public void testLinkedKeys() {
    Multimap<String, Integer> map = create();
    map.put("bar", 1);
    map.put("foo", 2);

  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemovePropagatesToMultimap() {
    assertTrue(multimap().entries().remove(mapEntry(k0(), v0())));
    expectMissing(mapEntry(k0(), v0()));
    assertEquals(getNumElements() - 1, multimap().size());
    assertFalse(multimap().containsEntry(k0(), v0()));
  }

      checkNonNegative(--selfLoopCount);
    }
    N previousNode = inEdgeMap.remove(edge);
    // We're relying on callers to call this method only with an edge that's in the graph.
    return requireNonNull(previousNode);
  }

  @Override
  public N removeOutEdge(E edge) {
    N previousNode = outEdgeMap.remove(edge);
    // We're relying on callers to call this method only with an edge that's in the graph.

        docMap.put("key1", "value1");
        docMap.put("key2", "value2");

        assertEquals("value1", docMap.remove("key1"));
        assertNull(docMap.get("key1"));
        assertFalse(docMap.containsKey("key1"));

        assertNull(docMap.remove("nonexistent"));

        assertEquals(1, docMap.size());
        assertTrue(docMap.containsKey("key2"));
    }

    assertEquals(Integer.valueOf(50), asMap.get(10));
    assertEquals(Integer.valueOf(79), cache.getIfPresent(2));
    assertEquals(Integer.valueOf(79), asMap.get(2));

    asMap.remove(10, 100);
    asMap.remove(2, 79);

    assertEquals(Integer.valueOf(50), cache.getIfPresent(10));
    assertEquals(Integer.valueOf(50), asMap.get(10));
    assertEquals(null, cache.getIfPresent(2));

public class EmptyIterator<T> implements Iterator<T> {

    /**
     * Creates an {@link EmptyIterator}.
     */
    public EmptyIterator() {
    }

    @Override
    public void remove() {
        throw new ClUnsupportedOperationException("remove");
    }

    @Override
    public boolean hasNext() {
        return false;
    }

    @Override
    public T next() {

        exception.expect(ClUnsupportedOperationException.class);
        exception.expectMessage(is("remove"));
        final Vector<String> vector = new Vector<String>();
        vector.add("a");
        final EnumerationIterator<String> itr = new EnumerationIterator<String>(vector.elements());
        itr.remove();
    }

    /**
     * @throws Exception
     */
    @Test

          nextEntry = entry.successorInValueSet;
          return result;
        }

        @Override
        public void remove() {
          checkForComodification();
          checkState(toRemove != null, "no calls to next() since the last call to remove()");
          ValueSet.this.remove(toRemove.getValue());
          expectedModCount = modCount;
          toRemove = null;
        }
      };
    }