docs: function(dict, progressive, options) {
  
                  /**
                   * Dictionary hash.
                   * @type {Object.<string,number>}
                   */
                  this.dict = {};
  
                  /**
                   * Next dictionary index.
                   * @type {number}
                   */
                  this.next = 0;
                  if (dict && Array.isArray(dict)) {
                      while (this.next < dict.length) {
                          this.dict[dict[this.next]] = this.next++;
                      }
                  }
  
                  /**
                   * Whether the encoder is progressive or static.
                   * @type {boolean}
                   */
                  this.progressive = !!progressive;
  
                  /**
                   * Options.
                   * @type {Object.<string,*>}
                   */
                  this.options = options || {};
              }