*/
  @Override
  public String toString() {
    if (isEmpty()) {
      return "[]";
    }
    StringBuilder builder = new StringBuilder(length() * 5); // rough estimate is fine
    builder.append('[').append(array[start]);

    for (int i = start + 1; i < end; i++) {
      builder.append(", ").append(array[i]);
    }
    builder.append(']');

              ListenableFuture<String> a, ListenableFuture<String> b) {
            return successfulAsList(ImmutableSet.of(a, b));
          }
        };
  }

  /**
   * Very rough equivalent of a timed get, produced by calling the no-arg get method in another
   * thread and waiting a short time for it.
   *

              ListenableFuture<String> a, ListenableFuture<String> b) {
            return successfulAsList(ImmutableSet.of(a, b));
          }
        };
  }

  /**
   * Very rough equivalent of a timed get, produced by calling the no-arg get method in another
   * thread and waiting a short time for it.
   *

thinking over other children she knew, who might do very well as
pigs, and was just saying to herself, `if one only knew the right
way to change them--' when she was a little startled by seeing
the Cheshire Cat sitting on a bough of a tree a few yards off.

  The Cat only grinned when it saw Alice.  It looked good-
natured, she thought:  still it had VERY long claws and a great
many teeth, so she felt that it ought to be treated with respect.

thinking over other children she knew, who might do very well as
pigs, and was just saying to herself, `if one only knew the right
way to change them--' when she was a little startled by seeing
the Cheshire Cat sitting on a bough of a tree a few yards off.

  The Cat only grinned when it saw Alice.  It looked good-
natured, she thought:  still it had VERY long claws and a great
many teeth, so she felt that it ought to be treated with respect.