Add / override static properties of this class.

Ext.define('My.cool.Class', {
...
});

My.cool.Class.addStatics({
someProperty: 'someValue',      // My.cool.Class.someProperty = 'someValue'
method1: function() { ... },    // My.cool.Class.method1 = function() { ... };
method2: function() { ... }     // My.cool.Class.method2 = function() { ... };
});

@param {Object} members
@return {Ext.Base} this
@static
@inheritable
function(members) {
            var member, name;

            for (name in members) {
                if (members.hasOwnProperty(name)) {
                    member = members[name];
                    if (typeof member == 'function' && !member.$isClass && member !== Ext.emptyFn && member !== Ext.identityFn) {
                        member.$owner = this;
                        member.$name = name;
                        //<debug>
                        member.displayName = Ext.getClassName(this) + '.' + name;
                        //</debug>
                    }
                    this[name] = member;
                }
            }

            return this;
        }