Magento backend_model not triggering on load and save - php

Question

This is a wierd situation because magento is loading my backend model, its just not calling it when I load and save it. I know this because 1. I see it in my database, 2. when I rename my backend model, my test case fails. Here is my code
It saves my values just fine and completely ignores my afterload and beforesave methods.
TEST CASE
<?php
class Super_Base_Test_Controller_Test extends EcomDev_PHPUnit_Test_Case_Controller {
const DEFAULTSTORE = 1;
public function setUpMocks() {
$this->setCurrentStore(1);
$customer = Mage::getSingleton('customer/customer')
->load(1);
$customer->setCoinBalance(20)
->save();
}
public function setUp() {
$this->setUpMocks();
$data = array(
'customer_id'=>1,
'message'=>'this is a test message',
'income'=>20,
'created_at'=>'9/11/84',
'updated_at'=>'9/11/84',
'current'=>1
);
$this->getRequest()->setParams($data);
}
protected function getTearDownOperation() {
return PHPUnit_Extensions_Database_Operation_Factory::TRUNCATE();
}
}
backend model
<?php
/**
* Created by PhpStorm.
* User: numerical25
* Date: 3/8/14
* Time: 6:22 PM
*/
class Super_Coin_Model_Customer_Attribute_Coinbalance extends Mage_Eav_Model_Entity_Attribute_Backend_Abstract {
protected function _afterLoad()
{
if (!is_array($this->getValue())) {
$value = $this->getValue();
$this->setValue(empty($value) ? false : unserialize($value));
}
}
protected function _beforeSave() {
if (is_array($this->getValue())) {
$this->setValue(serialize($this->getValue()));
}
}
public function setCoinAmount($amount) {
$this->setValue($amount);
}
}
installation file
$eavsetup->addAttribute('customer', 'coin_balance', array(
'input' => 'text',
'type' => 'decimal',
'label' => 'Customer Coin Balance',
'backend' => 'coin/customer_attribute_coinbalance',
'global' => 1,
'visible' => 1,
'required' => 0,
'user_defined' => 1, ));
When I set break points, the system completly ignores my methods.

Answer 1

Look at abstract class Mage_Eav_Model_Entity_Attribute_Backend_Abstract. It contains the following public methods: beforeSave() and afterLoad().
There are no _afterLoad() and _beforeSave() methods in that class