# File lib/dm-core/model.rb, line 199
    def properties(repository_name = default_repository_name)
      # We need to check whether all relations are already set up.
      # If this isn't the case, we try to reload them here
      if !@_valid_relations && respond_to?(:many_to_one_relationships)
        @_valid_relations = true
        begin
          many_to_one_relationships.each do |r|
            r.child_key
          end
        rescue NameError
          # Apparently not all relations are loaded,
          # so we will try again later on
          @_valid_relations = false
        end
      end
      @properties[repository_name] ||= repository_name == Repository.default_name ? PropertySet.new : properties(Repository.default_name).dup
    end