minor fix

MemeShare/app/src/main/java/com/pratyakshkhurana/funmemes/MainActivity.kt

@@ -46,7 +46,6 @@ class MainActivity : AppCompatActivity() {
         // Instantiate the RequestQueue.
         progress_bar_loading.visibility = View.VISIBLE
         //when meme is loading progress bar will load
-        val queue = Volley.newRequestQueue(this)
         val url = "https://meme-api.herokuapp.com/gimme"
         // api call is done to fetch image of meme
 
@@ -88,7 +87,7 @@ class MainActivity : AppCompatActivity() {
             })
 
         // Add the request to the RequestQueue.
-        queue.add(jsonObjectRequest)
+        MySingleton.getInstance(this).addToRequestQueue(jsonObjectRequest)
     }
 
     fun nextMeme(view: View) {

MemeShare/app/src/main/java/com/pratyakshkhurana/funmemes/MySingleton.kt

@@ -0,0 +1,31 @@
+package com.pratyakshkhurana.funmemes
+
+import android.content.Context
+import com.android.volley.Request
+import com.android.volley.RequestQueue
+import com.android.volley.toolbox.Volley
+
+//Singleton class is the one , it has only one instance
+//so app can call one request at at time
+//so we call using singleton and follow singleton pattern
+class MySingleton constructor(context: Context) {
+    companion object {
+        //volatile to make thread safe, ensure safety
+        @Volatile
+        private var INSTANCE: MySingleton? = null
+        fun getInstance(context: Context) =
+            INSTANCE ?: synchronized(this) {
+                INSTANCE ?: MySingleton(context).also {
+                    INSTANCE = it
+                }
+            }
+    }
+    private val requestQueue: RequestQueue by lazy {
+        // applicationContext is key, it keeps you from leaking the
+        // Activity or BroadcastReceiver if someone passes one in.
+        Volley.newRequestQueue(context.applicationContext)
+    }
+    fun <T> addToRequestQueue(req: Request<T>) {
+        requestQueue.add(req)
+    }
+}