I can not retrieve the getKey from an object in Firebase

I'm not able to rescue a child's pushId from Firebase.

In the mClientDatabaseReference.addValueEventListener > > onDataChange I get the value but I can not assign it to the object.

// Carrega os dados do mClienteAutoComplete
        mClientDatabaseReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {

            clientList = new ArrayList<>();

            for (DataSnapshot dados: dataSnapshot.getChildren()) {
                dados.getKey();  <-- OBJETO QUE NÃO CONSIGO ADICIONAR
                Client client = dados.getValue(Client.class);
                clientList.add(client);
            }

            ClientAutoCompleteAdapter adapter = new ClientAutoCompleteAdapter(LoansAddActivity.this, clientList);
            mClienteAutoComplete.setAdapter(adapter);

            Toast.makeText(LoansAddActivity.this, "List: "+ mClienteAutoComplete, Toast.LENGTH_SHORT).show();

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
        }
    });

In the mClientAutoComplete.setOnItemClickListener method, I can retrieve any data in my Client model, but I can not retrieve the object identifier from the Ex:

mClienteAutoComplete.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                Client clientItem = (Client) adapterView.getItemAtPosition(i);
                Toast.makeText(LoansAddActivity.this, "Client item: '"+clientItem.getNome()+"'", Toast.LENGTH_SHORT).show(); // CONSIGO PEGAR O VALOR getNome, getTelefone... menos a pushId do registro
            }
        });

In my model class do I have to reference something for the object to recognize the object identifier?

Follow the MODEL code:

package com.deson.agiemprestimos.model;

/**
 * Created by Deson on 18/04/2018.
 */

public class Client {

private String nome;
private String telefone;
private String cpf;
private String rg;
private String rua;
private String bairro;

public Client() {
}

public Client(String nome, String telefone, String cpf, String rg, String rua, String bairro) {
    this.nome     = nome;
    this.telefone = telefone;
    this.cpf      = cpf;
    this.rg       = rg;
    this.rua      = rua;
    this.bairro   = bairro;
}

public String getNome() {
    return nome;
}

public void setNome(String nome) {
    this.nome = nome;
}

public String getTelefone() {
    return telefone;
}

public void setTelefone(String telefone) {
    this.telefone = telefone;
}

public String getCpf() {
    return cpf;
}

public void setCpf(String cpf) {
    this.cpf = cpf;
}

public String getRg() {
    return rg;
}

public void setRg(String rg) {
    this.rg = rg;
}

public String getRua() {
    return rua;
}

public void setRua(String rua) {
    this.rua = rua;
}

public String getBairro() {
    return bairro;
}

public void setBairro(String bairro) {
    this.bairro = bairro;
}

}