docs: function (array, block, cb) {
              var promises, ret;
              if (block) {
                  ret = when(array.map(function (i) {
                      return this.insert(block(i));
                  }, this));
              } else {
                  ret = when(array.map(function (i) {
                      return this.insert(i);
                  }, this));
              }
              return ret.classic(cb).promise();
          }