import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * An immutable object that may contain a non-null reference to another object. Each instance of
 * this type either contains a non-null reference, or contains nothing (in which case we say that
 * the reference is "absent"); it is never said to "contain {@code null}".
 *
 * <p>A non-null {@code Optional<T>} reference can be used as a replacement for a nullable {@code T}

   */
  int size();

  /**
   * Returns {@code true} if this multimap contains no key-value pairs. Equivalent to {@code size()
   * == 0}, but can in some cases be more efficient.
   */
  boolean isEmpty();

  /**
   * Returns {@code true} if this multimap contains at least one key-value pair with the key {@code
   * key}.
   */

      }
    };
  }

  /**
   * Returns an unmodifiable <b>view</b> of the difference of two sets. The returned set contains
   * all elements that are contained by {@code set1} and not contained by {@code set2}. {@code set2}
   * may also contain elements not present in {@code set1}; these are simply ignored. The iteration
   * order of the returned set matches that of {@code set1}.
   *

  }

  @Override
  protected void expectMissing(Entry<K, V>... entries) {
    for (Entry<K, V> entry : entries) {
      assertFalse("Should not contain entry " + entry, actualContents().contains(entry));
      assertFalse(
          "Should not contain key " + entry.getKey() + " mapped to value " + entry.getValue(),
          equal(getMap().get(entry.getKey()), entry.getValue()));
    }
  }

              E e = itr2.next();
              if (!set1.contains(e)) {
                return e;
              }
            }
            return endOfData();
          }
        };
      }

      @Override
      public boolean contains(@Nullable Object object) {
        return set1.contains(object) || set2.contains(object);
      }

      @Override

        List<String> nameList = List.of(names);
        assertTrue(nameList.contains("file1.txt"), "Should contain file1.txt");
        assertTrue(nameList.contains("file2.txt"), "Should contain file2.txt");
        assertTrue(nameList.contains("subdir") || nameList.contains("subdir/"), "Should contain subdir");
    }

    @Test
    void testDirectoryDeletion() throws Exception {

        getList().removeAll(MinimalCollection.of(duplicate)));
    assertFalse(
        "after removeAll(e), a collection should not contain e even "
            + "if it initially contained e more than once.",
        getList().contains(duplicate));
  }

  // All other cases are covered by CollectionRemoveAllTester.

        getList().removeAll(MinimalCollection.of(duplicate)));
    assertFalse(
        "after removeAll(e), a collection should not contain e even "
            + "if it initially contained e more than once.",
        getList().contains(duplicate));
  }

  // All other cases are covered by CollectionRemoveAllTester.

// uuid cannot contain '[', ':' or ','.
func (o listPathOptions) encodeMarker(marker string) string {
	if o.ID == "" {
		// Mark as returning listing...
		return fmt.Sprintf("%s[minio_cache:%s,return:]", marker, markerTagVersion)
	}
	if strings.ContainsAny(o.ID, "[:,") {
		internalLogIf(context.Background(), fmt.Errorf("encodeMarker: uuid %s contained invalid characters", o.ID))
	}

  }

  /**
   * Delegates to {@link Collection#contains}. Returns {@code false} if the {@code contains} method
   * throws a {@code ClassCastException} or {@code NullPointerException}.
   */
  static boolean safeContains(Collection<?> collection, @Nullable Object object) {
    checkNotNull(collection);
    try {
      return collection.contains(object);
    } catch (ClassCastException | NullPointerException e) {