error: cannot find symbol class after in Android Studio

Question

I migrated to Android, so far a lot has been resolved, but I still have doubts in understanding the following errors:

• Erro: error: cannot find symbol class ListarDonos

package com.example.iury.livroapp;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.content.Intent;

public class SessaoDono extends AppCompatActivity {

    Button button_add_dono, button_list_donos;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sessao_dono);
        setTitle("Sessão dono");
        
        button_add_dono = findViewById(R.id.button_add_dono);
        button_list_donos = findViewById(R.id.button_list_donos);
      
        button_add_dono.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                Intent tela_add_dono = new Intent(getApplicationContext(),CadastrarDono.class);
                startActivity(tela_add_dono);
            }
        });
        button_list_donos.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                //error: cannot find symbol class ListarDonos
                Intent tela_list_donos = new Intent(getApplicationContext(),ListarDonos.class);
                startActivity(tela_list_donos);
            }
        });
    }
}

• Erro: error: cannot find symbol class ListarDonos

package com.example.iury.livroapp;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.content.Intent;

public class CadastrarDono extends AppCompatActivity {
    
    Button button_insert_dono, button_list_donos;
    EditText editNome_dono, editEmail_dono, editTelefone_dono;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_cadastrar_dono);
        setTitle("Cadastrar dono");
        
        button_insert_dono = findViewById(R.id.button_insert_dono);
        button_list_donos = findViewById(R.id.button_list_donos);
        editNome_dono = findViewById(R.id.editNome_dono);
        editEmail_dono = findViewById(R.id.editEmail_dono);
        editTelefone_dono = findViewById(R.id.editTelefone_dono);
        
        button_insert_dono.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v){
                String nome_dono = editNome_dono.getText().toString();
                String email_dono = editEmail_dono.getText().toString();
                String telefone_dono = editTelefone_dono.getText().toString();
                if(nome_dono.isEmpty() || email_dono.isEmpty() || telefone_dono.isEmpty()){
                    Toast.makeText(CadastrarDono.this,"Nenhum campo do formuário pode ficar vazio",Toast.LENGTH_SHORT).show();
                } else {
                    DatabaseHelperClass bd = new DatabaseHelperClass(CadastrarDono.this);
                    Dono dono = new Dono(nome_dono,email_dono,telefone_dono);
                    bd.InsertDono(dono);
                    Toast.makeText(CadastrarDono.this,"Dono adicionado com sucesso!",Toast.LENGTH_SHORT).show();
                    finish();
                    startActivity(getIntent());
                }
            }
        });
        button_list_donos.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                //error: cannot find symbol class ListarDonos
                Intent tela_list_donos = new Intent(getApplicationContext(),ListarDonos.class);
                startActivity(tela_list_donos);
            }
        });
    }
}