Object part = parts.next();
          if (part != null) {
            appendable.append(Joiner.this.toString(part));
            break;
          }
        }
        while (parts.hasNext()) {
          Object part = parts.next();
          if (part != null) {
            appendable.append(separator);
            appendable.append(Joiner.this.toString(part));
          }
        }

 * factories for I/O streams that provide many convenience methods that handle both opening and
 * closing streams for you.
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>
 * library. For more information on Sources and Sinks as well as other features of this package, see

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

/**
 * Basic utility libraries and interfaces.
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>
 * library.
 *
 * <h2>Contents</h2>
 *
 * The classes in this package that are most commonly useful are:
 *
 * <h3>String utilities</h3>
 *

 * the License.
 */

/**
 * Static utilities for the eight primitive types and {@code void}, and value types for treating
 * them as unsigned or storing them in immutable arrays.
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>
 * library.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/PrimitivesExplained">primitive utilities</a>.
 *

  public static final Charset UTF_16 = Charset.forName("UTF-16");

  /*
   * Please do not add new Charset references to this class, unless those character encodings are
   * part of the set required to be supported by all Java platform implementations! Any Charsets
   * initialized here may cause unexpected delays when this class is loaded. See the Charset

  /**
   * Files in the <a href="https://www.dartlang.org/articles/embedding-in-html/">dart</a>
   * programming language.
   *
   * @since 19.0
   */
  public static final MediaType DART_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "dart");

  /**
   * <a href="https://goo.gl/2QoMvg">Apple Passbook</a>.
   *
   * @since 19.0
   */

    long count = 1;
    double mean = checkFinite(values[0]);
    for (int index = 1; index < values.length; ++index) {
      checkFinite(values[index]);
      count++;
      // Art of Computer Programming vol. 2, Knuth, 4.2.2, (15)
      mean += (values[index] - mean) / count;
    }
    return mean;
  }

  /**

/**
 * Thread that finalizes referents. All references should implement {@code
 * com.google.common.base.FinalizableReference}.
 *
 * <p>While this class is public, we consider it to be *internal* and not part of our published API.
 * It is public so we can access it reflectively across class loaders in secure environments.
 *
 * <p>This class can't depend on other Guava code. If we were to load this class in the same class

  private double sumOfProductsOfDeltas = 0.0;

  /** Adds the given pair of values to the dataset. */
  public void add(double x, double y) {
    // We extend the recursive expression for the one-variable case at Art of Computer Programming
    // vol. 2, Knuth, 4.2.2, (16) to the two-variable case. We have two value series x_i and y_i.
    // We define the arithmetic means X_n = 1/n \sum_{i=1}^n x_i, and Y_n = 1/n \sum_{i=1}^n y_i.

   * </ul>
   */
  @CheckForNull private transient Object table;

  /**
   * Contains the logical entries, in the range of [0, size()). The high bits of each int are the
   * part of the smeared hash of the element not covered by the hashtable mask, whereas the low bits
   * are the "next" pointer (pointing to the next entry in the bucket chain), which will always be
   * less than or equal to the hashtable mask.