def attributes
      fields.each_with_object(HashWithIndifferentAccess.new) do |field, acc|
        acc[field.alias] = field.value
      end
    end
def attributes
      fields.each_with_object(HashWithIndifferentAccess.new) do |field, acc|
        acc[field.alias] = field.value
      end
    end
Initializes new instance of Filter class.
 Returns list of filter attributes.

 @return [HashWithIndifferentAccess]