App crashes after changing the mainactivity.kt

[gokul-bhoomi]

package dev.flutter.deep_links_flutter

import android.content.BroadcastReceiver
import android.os.Bundle
import android.content.Context
import android.content.Intent
import androidx.annotation.NonNull
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.EventChannel
import io.flutter.plugin.common.EventChannel.EventSink
import io.flutter.plugin.common.MethodChannel
import io.flutter.plugins.GeneratedPluginRegistrant

class MainActivity: FlutterActivity() {

private val CHANNEL = "poc.deeplink.flutter.dev/channel"
private val EVENTS = "poc.deeplink.flutter.dev/events"
private var startString: String? = null
private var linksReceiver: BroadcastReceiver? = null

override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
    GeneratedPluginRegistrant.registerWith(flutterEngine)

    MethodChannel(flutterEngine.dartExecutor, CHANNEL).setMethodCallHandler { call, result ->
        if (call.method == "initialLink") {
            if (startString != null) {
                result.success(startString)
            }
        }
    }

    EventChannel(flutterEngine.dartExecutor, EVENTS).setStreamHandler(
            object : EventChannel.StreamHandler {
                override fun onListen(args: Any?, events: EventSink) {
                    linksReceiver = createChangeReceiver(events)
                }

                override fun onCancel(args: Any?) {
                    linksReceiver = null
                }
            }
    )
}

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    val intent = getIntent()
    startString = intent.data?.toString()
}

override fun onNewIntent(intent: Intent) {
    super.onNewIntent(intent)
    if (intent.action === Intent.ACTION_VIEW) {
        linksReceiver?.onReceive(this.applicationContext, intent)
    }
}

fun createChangeReceiver(events: EventSink): BroadcastReceiver? {
    return object : BroadcastReceiver() {
        override fun onReceive(context: Context, intent: Intent) { // NOTE: assuming intent.getAction() is Intent.ACTION_VIEW
            val dataString = intent.dataString ?:
            events.error("UNAVAILABLE", "Link unavailable", null)
            events.success(dataString)
        }
    }
}

}