# File lib_core/rucy/message.rb, line 63
    def delete_header(name, pos=nil)
      normalized_name = Message.normalize_header(name)
      if (pos) then
        if (value_list = @header[normalized_name]) then
          del_val = value_list.delete_at(pos)
          if (value_list.empty?) then
            @header.delete(normalized_name)
          end
          return del_val
        end
      else
        return @header.delete(normalized_name)
      end

      nil
    end