Erro no Context como resolver ?

package br.com.alura.agenda;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
        List<String> alunos = new ArrayList<>(
                Arrays.asList("Jorge Costa", "Paulo Eremita", "Deziele"));
        ListView listaDeAlunos = findViewById(R.id.activity_main_lista_de_alunos);
        listaDeAlunos.setAdapter(new ArrayAdapter<String>(
                Context: this,
                android.R.layout.simple_list_item_1,
                alunos));