Function _keys

lib/assert.js:12–22

(obj)

 */

var _keys = function(obj){
    if(Object.keys) return Object.keys(obj);
    if (typeof obj != 'object' && typeof obj != 'function') {
        throw new TypeError('-');
    }
    var keys = [];
    for(var k in obj){
        if(obj.hasOwnProperty(k)) keys.push(k);
    }
    return keys;
};