model com relacionamentos

Plano.php

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password', 'admin', 'associado', 'cpf', 'nascimento', 'telefone', 'address_id', 'plano_id', 'cartao_id', 'indicacao_id'
    ];

    public function noticias(){
        return $this->hasMany('\App\Noticia');
    }

    public function contribuicoes(){
        return $this->hasMany('\App\Contribuicao');
    }

    //USUÁRIO TEM UM FK_ADDRESS 
    public function address(){
        return $this->belongsTo("\App\Address", 'address_id');
    }
  
    //USUÁRIO TEM UM FK_PLANO 
    public function plano(){
        return $this->belongsTo("\App\Plano", 'plano_id');
    }
    
     public function cartao(){
        return $this->belongsTo("\App\Cartao", 'cartao_id');
    }

    public $timestamps = true;
    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];


}