Ferret debugging

Is there any way to debug processes of creating/updating of index and
data retrieval?
I use ferret (0.10.13) and acts_as_ferret plugin, and it seems that
index is being updated - field ‘state_or_province_or_region’ has value
‘ON’:

ferret_create/update: Entity : 1
creating doc for class: Entity, id: 1
Adding field description with value ‘Sed metus lorem, pellentesque ac,
dignissim mattis, pellentesque sit amet, est. Aliquam id urna non lorem
convallis ornare’ to index
Adding field name with value ‘Sed sodales’ to index
Adding field address_zip_or_postal_code with value ‘99927’ to index
Adding field address_country with value ‘Canada’ to index
Adding field state_or_province_or_region with value ‘ON’ to index
Adding field type_name with value ‘Premium’ to index
Adding field address_city with value ‘Point Baker’ to index
Adding field approval_condition with value ‘approved’ to index

When I try to find this Entity as

Entity.find_by_contents(‘ON’)

I’ve got nothing:

id_score_model array: []
Query: ON
Result ids: [],
result:

even if I use ‘ON*’ as query:

id_score_model array: []
Query: ON*
Result ids: [],
result:

Any help will be very appreciated

Sorry for disturbing. I have found solution in this post
http://www.ruby-forum.com/topic/50059#16197