     properties: %{} # description, fieldName
   end
 
+  defmodule UpdateColumn do
+    defstruct fieldName: nil,
+      fourfour: nil,
+      properties: %{} # description, fieldName
+  end
+
   defmodule CreateColumns do
     defstruct columns: []
   end

        {:ok, list} -> Enum.map(list, fn result -> {:ok, result} end)
        {:error, _} = err -> Enum.map(ccs, fn _ -> err end)
      end
    end
  end


    %{ w | operations: [operation | w.operations] }
  end

  def update_column(%Write{} = w, fourfour, field_name, properties) do
    operation = %UpdateColumn{fourfour: fourfour, fieldName: field_name, properties: properties}
    %{ w | operations: [operation | w.operations] }
  end

  def drop_column(%Write{} = w, fourfour, field_name, properties) do
    operation = %DropColumn{field_name: field_name, fourfour: fourfour, properties: properties}
    %{ w | operations: [operation | w.operations] }
