# File lib/mail/parsers/rfc2822.rb, line 1549
    def _nt_word
      start_index = index
      if node_cache[:word].has_key?(index)
        cached = node_cache[:word][index]
        @index = cached.interval.end if cached
        return cached
      end

      i0 = index
      r1 = _nt_atom
      if r1
        r0 = r1
      else
        r2 = _nt_quoted_string
        if r2
          r0 = r2
        else
          @index = i0
          r0 = nil
        end
      end

      node_cache[:word][start_index] = r0

      r0
    end