Ошибка an operation is not implemented

Getting this Error

kotlin.NotImplementedError: An operation is not implemented: not implemented

I am implementing an ImageButton click listener

Requirement :- I want to perform an action on imagebutton click , but getting the above mentioned error

Correct me and also if there is any other work around to implement imagebutton click listener, do provide it , Thanks

Here is the fragment java class

class FragmentClass : Fragment(), View.OnClickListener {
    override fun onClick(v: View?) {
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
        when (v?.id) {
            R.id.back_icon -> {
                Toast.makeText(activity, "back button pressed", Toast.LENGTH_SHORT).show()
                activity.onBackPressed()
            }

            else -> {
            }
        }
    }

    override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        val view: View = inflater!!.inflate(R.layout.fragment_class, container,
                false)
        val activity = getActivity()
        var input_name = view.findViewById(R.id.input_name) as EditText
        var tv_addbucket = view.findViewById(R.id.tv_addbucket) as TextView
        val back_icon: ImageButton = view.findViewById(R.id.back_icon)
        back_icon.setOnClickListener(this)

        tv_addbucket.setOnClickListener(View.OnClickListener {
            Toast.makeText(activity, input_name.text, Toast.LENGTH_SHORT).show()
        })


        return view;
    }


}

and then the fragment_class. xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:id="@+id/header"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:focusable="true"
        android:focusableInTouchMode="true"
        android:clickable="true"
        android:padding="10dp">

        <ImageButton
            android:id="@+id/back_icon"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:background="#0000"
            android:focusable="true"
            android:focusableInTouchMode="true"
            android:clickable="true"
            android:src="@drawable/back_icon" />

        <TextView
            android:id="@+id/tv_header"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:text="Add Bucket" />
    </RelativeLayout>

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/header"
        android:fillViewport="true">

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="match_parent"

            android:layout_marginTop="?attr/actionBarSize"
            android:orientation="vertical"
            android:paddingLeft="20dp"
            android:paddingRight="20dp"
            android:paddingTop="60dp">

            <android.support.design.widget.TextInputLayout
                android:id="@+id/input_layout_name"
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <EditText
                    android:id="@+id/input_name"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="Bucket Name"
                    android:singleLine="true" />
            </android.support.design.widget.TextInputLayout>


            <TextView
                android:id="@+id/tv_addbucket"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="40dp"
                android:background="@drawable/blue_stroke_background"
                android:gravity="center"
                android:padding="15dp"
                android:text="Add"
                android:textColor="@color/white" />


        </LinearLayout>
    </ScrollView>

</RelativeLayout>

NotImplementedError

class NotImplementedError : Error

An exception is thrown to indicate that a method body remains to be implemented.

Constructors

NotImplementedError(
    message: String = "An operation is not implemented.")

«NotImplementedException» is thrown when the control goes into a method that has been declared but has not been implemented completely. Please find below the sample code example from MSDN :-

Sub Main()
    Try
        FutureFeature()
    Catch NotImp As NotImplementedException
        Console.WriteLine(NotImp.Message)
    End Try


End Sub

Sub FutureFeature()
    
    Throw New NotImplementedException()
End Sub

In the above example FutureFeature method method has not been implemented completely and the statement «Throw New NotImplementedException» throws the exception which is being caught in the catch block of your code. Please debug the code line by line (with F11) to know the exact method throwing the exception. Please visit https://msdn.microsoft.com/en-us/library/system.notimplementedexception(v=vs.110).aspx
for more details