[bugfix] fix index.flow.js

what:
why:
how:

lib/index.flow.js

@@ -1,36 +1,36 @@
-declare export function getAttr (el: Node, attrName: string): Attr;
-  declare export function setAttr (el: Node, attrName: string, attrVa: Attr): void;
-  declare export function addClassName (el: Node, cls: string): void;
-  declare export function removeClassName (el: Node, cls: string): void;
-  declare export function hasClassName (el: Node, cls: string): boolean;
-  declare export function removeEvent (el: Node, type: string, handler: Function, once?: boolean, capture?: boolean): void;
-  declare export function addEvent (el: Node, type: string, handler: Function, once?: boolean, capture?: boolean): void;
-  declare export function addDelegate (el: Node, selector: string, type: string, handler: Function, capture: boolean): void; 
-  declare export function removeDelegate (el: Node, selector: string, type: string, handler: Function, capture: boolean): void;
-  declare export function getStyle (el: Node, key: string): string;
-  declare export function setStyle (el: Node, key: string, val: string | number): void;
-  declare export function query (selector: string, container?: Node, toArray: boolean): Array<Node>;
-  declare export function removeEl (el: Node): void;
-  declare export function findParents (el: Node, endEl?: Node, haveEl: boolean, haveEndEl: boolean): Array<Node>;
-  declare export function $ (selector: string | Node, container?: Node): NodeWrap;
-  declare export class NodeWrap {
-    each (...args: Array<Function>): NodeWrap;
-    push (...args: Array<Node>): NodeWrap;
-    splice (start: number, count: number): NodeWrap;
-    find (selector: string): NodeWrap;
-    append (childEls: Node): NodeWrap;
-    appendTo (childEls: Node): NodeWrap;
-    text (val: string): NodeWrap;
-    html (html: string): NodeWrap;
-    attr  (name: string, val: string | number | boolean): NodeWrap;
-    data (key: string, val?: string | number | boolean | void): NodeWrap;
-    css (key: string, val?: string): NodeWrap;
-    addClass (cls: string): NodeWrap;
-    removeClass (cls: string): NodeWrap;
-    hasClass (cls: string): NodeWrap;
-    on (type: string, handler: Function, once?: boolean, capture?: boolean): NodeWrap;
-    off (type: string, handler: Function, once?: boolean, capture?: boolean): NodeWrap;
-    delegate (selector: string, type: string, handler: Function, capture: boolean): NodeWrap;
-    undelegate (selector: string, type: string, handler: Function, capture: boolean): NodeWrap;
-    remove (): NodeWrap;
-  }
+declare export function getAttr (el: Node, attrName: string): string | null;
+declare export function setAttr (el: Node, attrName: string, attrVa: any): void;
+declare export function addClassName (el: Node, cls: string): void;
+declare export function removeClassName (el: Node, cls: string): void;
+declare export function hasClassName (el: Node, cls: string): boolean;
+declare export function removeEvent (el: Node, type: string, handler: Function, once?: boolean, capture?: boolean): void;
+declare export function addEvent (el: Node, type: string, handler: Function, once?: boolean, capture?: boolean): void;
+declare export function addDelegate (el: Node, selector: string, type: string, handler: Function, capture: boolean): void; 
+declare export function removeDelegate (el: Node, selector: string, type: string, handler: Function, capture: boolean): void;
+declare export function getStyle (el: Node, key: string): string;
+declare export function setStyle (el: Node, key: string, val: string | number): void;
+declare export function query (selector: string, container?: Node, toArray: boolean): Array<Node>;
+declare export function removeEl (el: Node): void;
+declare export function findParents (el: Node, endEl?: Node, haveEl: boolean, haveEndEl: boolean): Array<Node>;
+declare export function $ (selector: string | Node, container?: Node): NodeWrap;
+declare export class NodeWrap {
+  each (...args: Array<Function>): NodeWrap;
+  push (...args: Array<Node>): NodeWrap;
+  splice (start: number, count: number): NodeWrap;
+  find (selector: string): NodeWrap;
+  append (childEls: Node): NodeWrap;
+  appendTo (childEls: Node): NodeWrap;
+  text (val: string): NodeWrap;
+  html (html: string): NodeWrap;
+  attr  (name: string, val: string | number | boolean): NodeWrap;
+  data (key: string, val?: string | number | boolean | void): NodeWrap;
+  css (key: string, val?: string): NodeWrap;
+  addClass (cls: string): NodeWrap;
+  removeClass (cls: string): NodeWrap;
+  hasClass (cls: string): NodeWrap;
+  on (type: string, handler: Function, once?: boolean, capture?: boolean): NodeWrap;
+  off (type: string, handler: Function, once?: boolean, capture?: boolean): NodeWrap;
+  delegate (selector: string, type: string, handler: Function, capture: boolean): NodeWrap;
+  undelegate (selector: string, type: string, handler: Function, capture: boolean): NodeWrap;
+  remove (): NodeWrap;
+}