'Opposite to .only(), exclude some document\'s fields. ::
post = BlogPost.objects(...).exclude(\'comments\')
.. note :: `exclude()` is chainable and will perform a union ::
So with the following it will exclude both: `title` and `author.name`::
post = BlogPost.objects.exclude(\'title\').exclude(\'author.name\')
:func:`~mongoengine.queryset.QuerySet.all_fields` will reset any
field filters.
:param fields: fields to exclude
.. versionadded:: 0.5'

def exclude(self, *fields):

    fields = {f: QueryFieldList.EXCLUDE for f in fields}
    return self.fields(**fields)
