code: def get_dot_atom_text(value):
      
      dot_atom_text = DotAtomText()
      if not value or value[0] in ATOM_ENDS:
          raise errors.HeaderParseError("expected atom at a start of "
              "dot-atom-text but found '{}'".format(value))
      while value and value[0] not in ATOM_ENDS:
          token, value = get_atext(value)
          dot_atom_text.append(token)
          if value and value[0] == '.':
              dot_atom_text.append(DOT)
              value = value[1:]
      if dot_atom_text[-1] is DOT:
          raise errors.HeaderParseError("expected atom at end of dot-atom-text "
              "but found '{}'".format('.'+value))
      return dot_atom_text, value
docs: dot-text = 1*atext *("." 1*atext)