def attribute_lookup(assoc)
      group_data = @map[assoc.group.to_sym]
      return nil unless group_data

      attribute = group_data[assoc.type.to_sym]
      return attribute
    end
def attribute_lookup(assoc)
      group_data = @map[assoc.group.to_sym]
      return nil unless group_data

      attribute = group_data[assoc.type.to_sym]
      return attribute
    end
Extracts the attribute definition for a given association