'Override this method to make customised updates to the object
when a file is going to be stored.
This may be used to parse file content and extract values for
additional fields.
Note: as populate_obj() on form fields my be called in an arbitrary
order, do not assume that other fields in obj have been correctly set.
If an extra information (from other fields) is necessary for parsing
the supplied file content, a form-field validator may be used to copy
it directly from the form to this field.
:param obj: model object
:param byte_stream: file contents'

def process_on_store(self, obj, byte_stream):

    pass
