Android take Run-time Call Permission & Make Call

MainActivity.java

package khan.arif.practise;

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;


public class MainActivity extends AppCompatActivity {
    private Button call;
    private EditText number;
    private int REQUEST_CALL_PHONE = 34;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        number = (EditText) findViewById(R.id.number);

        call = (Button) findViewById(R.id.call);
        call.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                makeCall();
            }
        });
    }

    public void makeCall(){
        String tel = "tel:" + number.getText().toString();
        Intent call = new Intent(Intent.ACTION_CALL);
        call.setData(Uri.parse(tel));

        if (ActivityCompat.checkSelfPermission(Main2Activity.this, Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(Main2Activity.this, new String[]{Manifest.permission.CALL_PHONE}, REQUEST_CALL_PHONE);
            return;
        }
        startActivity(call);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        if(requestCode == REQUEST_CALL_PHONE){
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                makeCall();
            }
        }
    }
}