code: def type_path_to(storable)
        shortest = nil
        holds_storage_types.each do |st|
          stp = st.path_to(storable) || next
          shortest = stp if shortest.nil? or stp.size < shortest.size
        end
        shortest
      end
docs: Returns a StorageType array of descendant StorageTypes which can hold the given storable,
   or nil if no such path exists.
  
   @param [Storable] the domain object to store in this container
   @return [<StorageType>] the {StorageType}s leading from this container to the storable holder