public function validationUserName(Validator $validator) {
		$validator->setProvider('userTable', $this->_table);

		$validator->add($this->_field('username'), [
			'notBlank' => [
				'rule' => 'notBlank',
				'message' => __d('user_tools', 'An username is required.')
			],
			'length' => [
				'rule' => ['lengthBetween', 3, 32],
				'message' => __d('user_tools', 'The username must be between 3 and 32 characters.')
			],
			'unique' => [
				'rule' => ['validateUnique', ['scope' => 'username']],
				'provider' => 'userTable',
				'message' => __d('user_tools', 'The username is already in use.')
			],
			'alphaNumeric' => [
				'rule' => 'alphaNumeric',
				'message' => __d('user_tools', 'The username must be alpha numeric.')
			]
		]);

		return $validator;
	}