.addEqualityGroup(
            singleton(1),
            union(singleton(1), singleton(1)),
            intersection(newHashSet(1, 2), newHashSet(1, 3)),
            difference(newHashSet(1, 2), newHashSet(2, 3)),
            symmetricDifference(newHashSet(1, 2, 3), newHashSet(2, 3)))
        .addEqualityGroup(
            singleton(2),
            union(singleton(2), singleton(2)),

    Collection<String> c = MinimalCollection.of("a");
    Set<String> set = copyOf(c);
    assertEquals(singleton("a"), set);
  }

  public void testCopyOf_collection_oneElementRepeated() {
    Collection<String> c = MinimalCollection.of("a", "a", "a");
    Set<String> set = copyOf(c);
    assertEquals(singleton("a"), set);
  }

  public void testCopyOf_collection_general() {

            }
        }
    }

    @Singleton
    @Named(Lifecycle.CLEAN)
    @SuppressWarnings("unused")
    static class CleanLifecycleProvider extends BaseLifecycleProvider {
        CleanLifecycleProvider() {
            super(Lifecycle.CLEAN);
        }
    }

    @Singleton
    @Named(Lifecycle.DEFAULT)
    @SuppressWarnings("unused")

    assertEquals(singleton("bar"), set);
    set.clear();
    assertTrue(set.isEmpty());
    assertEquals(singleton("foo"), sortedTable.rowKeySet());
  }

  public void testRowKeySetTailSet() {
    sortedTable = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    Set<String> set = sortedTable.rowKeySet().tailSet("cat");
    assertEquals(singleton("foo"), set);
    set.clear();

    if (supportsRemove) {
      int initialSize = map.size();
      assertTrue(keys.removeAll(singleton(key)));
      assertEquals(initialSize - 1, map.size());
      assertFalse(map.containsKey(key));
    } else {
      assertThrows(UnsupportedOperationException.class, () -> keys.removeAll(singleton(key)));
    }
    assertInvariants(map);
  }

  public void testKeySetRetainAll() {

    assertEquals(ImmutableRangeSet.<Integer>all(), rangeSet.complement());
    assertFalse(rangeSet.contains(0));
    assertFalse(rangeSet.intersects(Range.singleton(0)));
    assertFalse(rangeSet.encloses(Range.singleton(0)));
    assertTrue(rangeSet.enclosesAll(rangeSet));
    assertTrue(rangeSet.isEmpty());
  }

  public void testAll() {

    if (supportsRemove) {
      int initialSize = map.size();
      assertTrue(keys.removeAll(singleton(key)));
      assertEquals(initialSize - 1, map.size());
      assertFalse(map.containsKey(key));
    } else {
      assertThrows(UnsupportedOperationException.class, () -> keys.removeAll(singleton(key)));
    }
    assertInvariants(map);
  }

  public void testKeySetRetainAll() {

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.di;

import javax.inject.Named;
import javax.inject.Singleton;

import java.nio.file.Path;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import com.google.inject.AbstractModule;
import com.google.inject.Binding;

    assertFalse(entries.contains(Maps.immutableEntry("foo", singleton(2))));
    assertFalse(entries.remove(Maps.immutableEntry("foo", singleton(2))));
    assertTrue(map.containsKey("foo"));
    assertTrue(entries.contains(Maps.immutableEntry("foo", singleton(1))));
    assertTrue(entries.remove(Maps.immutableEntry("foo", singleton(1))));
    assertFalse(map.containsKey("foo"));
  }

            new TestStringSetGenerator() {
              @Override
              public Set<String> create(String[] elements) {
                return singleton(elements[0]);
              }
            })
        .named("singleton")
        .withFeatures(
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.ALLOWS_NULL_VALUES,
            CollectionSize.ONE)