# File lib/mail/attachments_list.rb, line 31
    def []=(name, value)
      default_values = { :content_type => "#{set_mime_type(name)}; filename=\"#{name}\"",
                         :content_transfer_encoding => 'Base64',
                         :content_disposition => "attachment; filename=\"#{name}\"" }

      if value.is_a?(Hash)

        default_values[:body] = value.delete(:content) if value[:content]

        default_values[:body] = value.delete(:data) if value[:data]

        # Only force encode base64 if the user has not specified an encoding
        if value[:transfer_encoding]
          default_values[:content_transfer_encoding] = value.delete(:transfer_encoding)
        elsif value[:encoding]
          default_values[:content_transfer_encoding] = value.delete(:encoding)
        else
          default_values[:body] = Mail::Encodings::Base64.encode(default_values[:body])
        end

        if value[:mime_type]
          default_values[:content_type] = value.delete(:mime_type)
        end

        hash = default_values.merge(value)
      else
        default_values[:body] = Mail::Encodings::Base64.encode(value)
        hash = default_values
      end

      @parts_list << Part.new(hash)
    end