code: def folder_shape!(folder_shape)
        @nbuild.FolderShape {
          @nbuild.parent.default_namespace = @default_ns
          base_shape!(folder_shape[:base_shape])
          if(folder_shape[:additional_properties])
            additional_properties!(folder_shape[:additional_properties])
          end
        }
      end
docs: Build the FolderShape element
   @see http://msdn.microsoft.com/en-us/library/aa494311.aspx
   @param [Hash] folder_shape The folder shape structure to build from
   @todo need fully support all options