Shared instance used

ios/RNFetchBlobNetwork.h

 #import <Foundation/Foundation.h>
 #import "RNFetchBlobProgress.h"
 #import "RNFetchBlobFS.h"
+#import "RNFetchBlobRequest.h"
 
 #if __has_include(<React/RCTAssert.h>)
 #import <React/RCTBridgeModule.h>
 
 @interface RNFetchBlobNetwork : NSObject  <NSURLSessionDelegate, NSURLSessionTaskDelegate, NSURLSessionDataDelegate>
 
+@property(nonnull, nonatomic) NSOperationQueue *taskQueue;
+@property(nonnull, nonatomic) NSMapTable<NSString*, RNFetchBlobRequest*> * requestsTable;
 
-+ (_Nullable instancetype)sharedInstance;
++ (RNFetchBlobNetwork* _Nullable)sharedInstance;
 + (NSMutableDictionary  * _Nullable ) normalizeHeaders:(NSDictionary * _Nullable)headers;
 + (void) cancelRequest:(NSString * _Nonnull)taskId;
 + (void) emitExpiredTasks;

ios/RNFetchBlobNetwork.m

 #import "RNFetchBlob.h"
 #import "RNFetchBlobConst.h"
 #import "RNFetchBlobProgress.h"
-#import "RNFetchBlobRequest.h"
 
 #if __has_include(<React/RCTAssert.h>)
 #import <React/RCTRootView.h>
 
 @implementation RNFetchBlobNetwork
 
-NSOperationQueue *taskQueue;
-NSMapTable<NSString*, RNFetchBlobRequest*> * requestsTable;
 
 - (id)init {
     self = [super init];
     if (self) {
-        requestsTable = [NSMapTable mapTableWithKeyOptions:NSMapTableStrongMemory valueOptions:NSMapTableWeakMemory];
+        self.requestsTable = [NSMapTable mapTableWithKeyOptions:NSMapTableStrongMemory valueOptions:NSMapTableWeakMemory];
         
-        taskQueue = [[NSOperationQueue alloc] init];
-        taskQueue.qualityOfService = NSQualityOfServiceUtility;
-        taskQueue.maxConcurrentOperationCount = 10;
+        self.taskQueue = [[NSOperationQueue alloc] init];
+        self.taskQueue.qualityOfService = NSQualityOfServiceUtility;
+        self.taskQueue.maxConcurrentOperationCount = 10;
     }
     
     return self;
 }
 
-+ (instancetype)sharedInstance {
++ (RNFetchBlobNetwork* _Nullable)sharedInstance {
     static id _sharedInstance = nil;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
                   bridge:bridgeRef
                   taskId:taskId
              withRequest:req
-      taskOperationQueue:taskQueue
+      taskOperationQueue:[self sharedInstance].taskQueue
                 callback:callback];
     
     @synchronized([RNFetchBlobNetwork class]) {
-        [requestsTable setObject:request forKey:taskId];
+        [[self sharedInstance].requestsTable setObject:request forKey:taskId];
     }
 }
 
 {
     if (config) {
         @synchronized ([RNFetchBlobNetwork class]) {
-            [requestsTable objectForKey:taskId].progressConfig = config;
+            [[self sharedInstance].requestsTable objectForKey:taskId].progressConfig = config;
         }
     }
 }
 {
     if (config) {
         @synchronized ([RNFetchBlobNetwork class]) {
-            [requestsTable objectForKey:taskId].uploadProgressConfig = config;
+            [[self sharedInstance].requestsTable objectForKey:taskId].uploadProgressConfig = config;
         }
     }
 }
     NSURLSessionDataTask * task;
     
     @synchronized ([RNFetchBlobNetwork class]) {
-        task = [requestsTable objectForKey:taskId].task;
+        task = [[self sharedInstance].requestsTable objectForKey:taskId].task;
     }
     
     if(task && task.state == NSURLSessionTaskStateRunning) {