docs: function (obj) {
  
              var length = !!obj && "length" in obj && obj.length,
                  type   = $this.type(obj);
  
              if (type === "function" || $this.isWindow(obj)) {
                  return false;
              }
  
              return type === "array" ||
                  length === 0 ||
                  typeof length === "number" &&
                  length > 0 &&
                  (length - 1) in obj;
          }