import org.jspecify.annotations.Nullable;

/**
 * Static utility methods pertaining to the {@link Future} interface.
 *
 * <p>Many of these methods use the {@link ListenableFuture} API; consult the Guava User Guide
 * article on <a href="https://github.com/google/guava/wiki/ListenableFutureExplained">{@code
 * ListenableFuture}</a>.
 *

   * NavigableSet#subSet(Object, boolean, Object, boolean) subSet()}, {@link
   * NavigableSet#tailSet(Object, boolean) tailSet()}, and {@link NavigableSet#headSet(Object,
   * boolean) headSet()}) to actually construct the view. Consult these methods for a full
   * description of the returned view's behavior.
   *
   * <p><b>Warning:</b> {@code Range}s always represent a range of values using the values' natural