BRDrawe is a subclass of NSObject, instead of NSDrawer. It's like QQ for Mac.
##Usage
####init
- (instancetype)initWithContentSize:(NSSize)size preferredEdge:(NSRectEdge)edge
####control
- (IBAction)open:(nullable id)sender;
- (IBAction)close:(nullable id)sender;
- (IBAction)toggle:(nullable id)sender;
####Or
Interface Builder
For more details, see This blog.