diff --git a/CHANGELOG.md b/CHANGELOG.md
index b39359d..9d9e169 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.0.2
+
+* Added payload cancellation and other assertions 
+
 ## 1.0.1
 
 * Changed convinience methods for asking permissions(location+storage)
diff --git a/README.md b/README.md
index f555e2a..0a75adc 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # nearby_connections
 
-An **android** flutter plugin for the Nearby Connections API
+An **android** flutter plugin for the [Nearby Connections API]((https://developers.google.com/nearby/connections/overview))
 Currently supports Bytes and Files.
 
 [![pub package](https://img.shields.io/pub/v/nearby_connections.svg)](https://pub.dartlang.org/packages/nearby_connections)
diff --git a/android/src/main/java/com/pkmnapps/nearby_connections/NearbyConnectionsPlugin.java b/android/src/main/java/com/pkmnapps/nearby_connections/NearbyConnectionsPlugin.java
index b473614..d76677c 100644
--- a/android/src/main/java/com/pkmnapps/nearby_connections/NearbyConnectionsPlugin.java
+++ b/android/src/main/java/com/pkmnapps/nearby_connections/NearbyConnectionsPlugin.java
@@ -88,7 +88,7 @@ public class NearbyConnectionsPlugin implements MethodCallHandler {
                 break;
             case "askExternalStoragePermission":
                 ActivityCompat.requestPermissions(activity,
-                        new String[]{Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.WRITE_EXTERNAL_STORAGE},
+                        new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE},
                         0);
                 result.success(null);
                 break;
@@ -255,11 +255,19 @@ public class NearbyConnectionsPlugin implements MethodCallHandler {
                     result.success(filePayload.getId()); //return payload id to dart
                 } catch (FileNotFoundException e) {
                     Log.e("nearby_connections", "File not found", e);
-                    result.error("Failure", "File Not found", null);
+                    result.error("Failure", e.getMessage(), null);
                     return;
                 }
                 break;
             }
+            case "cancelPayload": {
+                String payloadId = (String) call.argument("payloadId");
+
+                assert payloadId != null;
+                Nearby.getConnectionsClient(activity).cancelPayload(Long.parseLong(payloadId));
+                result.success(null);
+                break;
+            }
             default:
                 result.notImplemented();
         }
@@ -367,13 +375,12 @@ public class NearbyConnectionsPlugin implements MethodCallHandler {
             args.put("endpointId", endpointId);
             args.put("payloadId", payload.getId());
             args.put("type", payload.getType());
-                        
+
             if (payload.getType() == Payload.Type.BYTES) {
                 byte[] bytes = payload.asBytes();
                 assert bytes != null;
                 args.put("bytes", bytes);
-            }
-            else if (payload.getType() == Payload.Type.FILE) {
+            } else if (payload.getType() == Payload.Type.FILE) {
                 args.put("filePath", payload.asFile().asJavaFile().getAbsolutePath());
             }
 
diff --git a/example/pubspec.lock b/example/pubspec.lock
index f4e1581..fb2d464 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -73,7 +73,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "1.0.1"
+    version: "1.0.2"
   path:
     dependency: transitive
     description:
diff --git a/lib/src/classes.dart b/lib/src/classes.dart
index 236ae78..bbff1b7 100644
--- a/lib/src/classes.dart
+++ b/lib/src/classes.dart
@@ -25,6 +25,8 @@ class Payload {
   });
 }
 
+/// Gives payload status (SUCCESS, FAILURE, IN_PROGRESS)
+/// bytes transferred and total bytes
 class PayloadTransferUpdate {
   int id, bytesTransferred, totalBytes;
   PayloadStatus status;
diff --git a/lib/src/nearby_connections.dart b/lib/src/nearby_connections.dart
index d2674f6..8267387 100644
--- a/lib/src/nearby_connections.dart
+++ b/lib/src/nearby_connections.dart
@@ -159,18 +159,20 @@ class Nearby {
   Future<void> askLocationPermission() async => await _channel.invokeMethod(
         'askLocationPermission',
       );
-  
+
   /// Convinience method
   ///
   /// retruns true/false based on external storage permissions.
-  Future<bool> checkExternalStoragePermission() async => await _channel.invokeMethod(
+  Future<bool> checkExternalStoragePermission() async =>
+      await _channel.invokeMethod(
         'checkExternalStoragePermission',
       );
 
   /// Convinience method
   ///
   /// Asks external storage permission, required for file
-  Future<void> askExternalStoragePermission() async => await _channel.invokeMethod(
+  Future<void> askExternalStoragePermission() async =>
+      await _channel.invokeMethod(
         'askExternalStoragePermission',
       );
 
@@ -252,6 +254,7 @@ class Nearby {
   /// this will call the onDisconnected method on callbacks of
   /// connected endPoint
   Future<void> disconnectFromEndpoint(String endpointId) async {
+    assert(endpointId != null);
     await _channel.invokeMethod(
         'disconnectFromEndpoint', <String, dynamic>{'endpointId': endpointId});
   }
@@ -274,6 +277,9 @@ class Nearby {
     this._discoverConnectionResult = onConnectionResult;
     this._discoverDisconnected = onDisconnected;
 
+    assert(endpointId != null);
+    assert(userNickName != null);
+
     return await _channel.invokeMethod(
       'requestConnection',
       <String, dynamic>{
@@ -298,6 +304,9 @@ class Nearby {
   }) async {
     this._onPayloadReceived = onPayLoadRecieved;
     this._onPayloadTransferUpdate = onPayloadTransferUpdate;
+
+    assert(endpointId != null);
+
     return await _channel.invokeMethod(
       'acceptConnection',
       <String, dynamic>{
@@ -316,6 +325,8 @@ class Nearby {
   /// [OnConnectionResult] is called on both
   /// even if one of them rejects the connection
   Future<bool> rejectConnection(String endpointId) async {
+    assert(endpointId != null);
+
     return await _channel.invokeMethod(
       'rejectConnection',
       <String, dynamic>{
@@ -333,6 +344,8 @@ class Nearby {
   /// Uint8List bytes = Uint8List.fromList(a.codeUnits);
   /// ```
   Future<void> sendBytesPayload(String endpointId, Uint8List bytes) async {
+    assert(endpointId != null);
+
     return await _channel.invokeMethod(
       'sendPayload',
       <String, dynamic>{
@@ -350,6 +363,8 @@ class Nearby {
   /// so that receiver can rename the file accordingly
   /// Send the payloadID and filename to receiver as bytes payload
   Future<int> sendFilePayload(String endpointId, String filePath) async {
+    assert(endpointId != null);
+
     return await _channel.invokeMethod(
       'sendFilePayload',
       <String, dynamic>{
@@ -358,4 +373,15 @@ class Nearby {
       },
     );
   }
+
+  Future<void> cancelPayload(int payloadId) async {
+    assert(payloadId != null);
+    
+    return await _channel.invokeMethod(
+      'cancelPayload',
+      <String, dynamic>{
+        'payloadId': payloadId.toString(),
+      },
+    );
+  }
 }
diff --git a/pubspec.yaml b/pubspec.yaml
index ffbe23a..79208e2 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: nearby_connections
 description: Plugin for the android NearbyConnections API. Bytes and Files Supported.
-version: 1.0.1
+version: 1.0.2
 author: Prerak Mann <mannprerak2@gmail.com>
 homepage: https://github.com/mannprerak2/nearby_connections