# File lib/mail/elements/content_transfer_encoding_element.rb, line 7
    def initialize( string )
      parser = Mail::ContentTransferEncodingParser.new
      case
      when string.blank?
        @encoding = ''
      when tree = parser.parse(string.to_s.downcase)
        @encoding = tree.encoding.text_value
      else
        raise Mail::Field::ParseError, "ContentTransferEncodingElement can not parse |#{string}|\nReason was: #{parser.failure_reason}\n"
      end
    end