Hi everyone, I'm calling a wizard with a context 

MODULE (Customer)

@api.multi
    def action_open_wizard(self):
        log.error(self.id) #<---- I see 123456
        return {
            'type': 'ir.actions.act_window',
            'name': 'Change Customer Field',
            'res_model': 'customer.change',
            'view_type': 'form',
            'view_mode': 'form',
            'target': 'new',
            'context': {
                #.....
                'default_customer_name': self.name,
                'default_age':self.age,
                'default_customer_id': self.id, #<---- current id
                #......
                        }
                }

in the context step the id of the element I'm modifying but when I press the button to save the id no longer exists​

WIZARD

...

customer_id = fields.Many2one('myaddon.customer')

....

@api.model
def doit(self):
        log.error(self.customer_id) #<--- False
        if self.customer_id:
            target = self.env['myaddon.customer'].browse(self.customer_id)

How can I solve it? Thanks in advance