ArchieR7

import UIKit

struct UISetting {
    static let blue = UIColor(colorLiteralRed: 21/255, green: 122/255, blue: 251/255, alpha: 1)
}

ArchieR7

 func testAsyncFunction() {
        let exp = expectation(description: "Async Expectation")
        NetworkManager.shared.update(data: Data(), completeHandler: {
            exp.fulfill()
        })
        waitForExpectations(timeout: 30, handler: nil)
    }

ArchieR7

dismiss(animated: true, completion: nil)

ArchieR7

[self.KVOController observe:self
                            keyPath:NSStringFromSelector(@selector(observeObjectName))
                            options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
                              block:^(id  _Nullable observer, id _Nonnull object, NSDictionary<NSString *,id> * _Nonnull change) {
                            //do something
}];

ArchieR7

- (void)observe:(nullable id)object keyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options block:(FBKVONotificationBlock)block;

ArchieR7

NS_ASSUME_NONNULL_BEGIN
  
@interface DemoObject : NSObject

@property (nonatomic) NSString *name;
@property (nonatomic, nullable) NSString *address;
@property (nonatomic, readonly) NSString *phoneNumber;

@end

ArchieR7

cd /var
touch swap.img
chmod 600 swap.img
dd if=/dev/zero of=/var/swap.img bs=1024k count=1000
mkswap /var/swap.img
swapon /var/swap.img
# swapoff /var/swap.img

ArchieR7

http {    
    proxy_buffer_size   128k;
    proxy_buffers   4 256k;
    proxy_busy_buffers_size   256k;

    fastcgi_buffer_size 128k;
    fastcgi_buffers 4 256k;
    fastcgi_busy_buffers_size 128k;
  
  ...

ArchieR7

#import "SingletonDemo.h"

@implementation SingletonDemo

+ (instancetype)shared {
    static ArchieSingleton *instance = nil;
    static dispatch_once_t once_token;
    dispatch_once(&once_token, ^{
        instance = [[ArchieSingleton alloc] init];
    });

ArchieR7

#import <UIKit/UIKit.h>

@interface SingletonDemo : NSObject

+ (instancetype)shared;

@end