code: def add_association_to_attribute_map(attribute, assoc)
        current = @attributes[attribute]
  
        # If there's already a value, we can safely ignore the empty association
        return if current && assoc.blank?
  
        case current
          when nil    then @attributes[attribute] = [assoc]
          when Array  then @attributes[attribute].push(assoc)
        end
      end
docs: Adds the given association to an array of associations for the given
   attribute