There are multiple states added like this:
'state':fields.selection([('new', 'New'), ('assigned','Assigneed'), ('in_progress', 'In Progress'),('resolved','Resolved'),('rejected','Rejected'),('closed','Closed')], 'Status')
An environment wraps data for ORM records:
'cr', the current database cursor.
'uid', the current user id.
'context', the current context dictionary.
In new API, self will represent/store current/class level information.
self.state will give you current state of record. You can use in any ORM method or function/computed fields as well.
For more about ORM reference