Hello odooers , I have to create a custom modules base on recruitment app , I want to create a Job position in same email address and the difference if we have a same email address I want to add a id to a new field name Email Subject , this is my create custom modules , and i  add the email subject field now I want to create the modal with no exception if the email address is existent I want to inherit new mail.alias.mixin but if I create the error shows that no existent model for hr.job , please odoo pro/master help me , I 'm new here!