百度了很多，但是hook Mac app的教程很少，我想学习下mac程序的逆向。取得一程序的h头文件如下：
#import
@class NSArray, NSImage, NSString;
@interface PCLocation : NSObject
{
BOOL _premium;
NSString *_code;
NSArray *_includes;
NSString *_name;
NSString *_tags;
NSString *_icon;
NSArray *_locations;
}
@property ( retain , nonatomic ) NSArray *locations; // @synthesize locations=_locations;
@property ( copy , nonatomic ) NSString *icon; // @synthesize icon=_icon;
@property ( nonatomic , getter =isPremium) BOOL premium; // @synthesize premium=_premium;
@property ( copy , nonatomic ) NSString *tags; // @synthesize tags=_tags;
@property ( copy , nonatomic ) NSString *name; // @synthesize name=_name;
@property ( readonly , nonatomic ) NSArray *includes; // @synthesize includes=_includes;
@property ( copy , nonatomic ) NSString *code; // @synthesize code=_code;
( void ).cxx_destruct;
( BOOL )isEqual:( id )arg1;
( id )initWithDictionary:( id )arg1 locations:( id )arg2;
@property ( readonly , nonatomic ) NSImage *flag;
@property ( readonly , nonatomic ) NSString *localizedName;
@end
求教大神们：在monkeydev中我想hook下面这句：
@property ( nonatomic , getter =isPremium) BOOL premium; // @synthesize
让它返回true,我不知道怎么写，试了无数次都没有成功，请你们帮帮我这个新手吧！