def find(by_index, value, options = {})
      raise Ork::IndexNotFound unless indices.has_key? by_index

      index = indices[by_index]
      Ork::ResultSet.new(self, index, value, options)
    end
def find(by_index, value, options = {})
      raise Ork::IndexNotFound unless indices.has_key? by_index

      index = indices[by_index]
      Ork::ResultSet.new(self, index, value, options)
    end
Find values in indexed fields.
   @return Ork::ResultSet<Document> found documents in the bucket

 options - Hash configs for pagination.
   :max_results  - Number
   :continuation - String

 Example:

   class User
     include Ork::Document

     attribute :name
     index :name
   end

   u = User.create(name: 'John')
   User.find(:name, 'John', max_results: 5).include?(u)
   # => true

   User.find(:name, 'Mike').include?(u)
   # => false

 Note: If the key was not defined, an
 `Ork::IndexNotFound` exception is raised.