code: protected DocType getDocType(AppendingStringBuffer response) {
  		String contentSoFar = getFirstCharacters(response, 128);
  
  		Matcher matcher = DOCTYPE_PATTERN.matcher(contentSoFar);
  		if (!matcher.find())
  			return null;
  
  		String docTypeStr = matcher.group();
  
  		if (Strings.isEmpty(docTypeStr))
  			return null;
  
  		DocType docType = DocType.getDocType(docTypeStr);
  		return docType;
  	}
docs: Gets the DOCTYPE from the response. Returns {@code null} when the DOCTYPE
  is not detected, or unknown. See {@link DocType} for supported DOCTYPEs.