code: public static Action stringContent(final String content, final Charset charset) {
          return composite(charset(charset), bytesContent(content.getBytes(charset)));
      }
docs: Writes string content into response. The passed charset is used:
  - To encoded the string into bytes;
  - As character set of the response.
  The latter will result in a <pre>charset=XXX</pre> part of <pre>Content-Type</pre> header
  if and only if the header has been set in some way (e.g. by using {@link #contentType(String)} action.
  
  See `integration.CharsetAndEncodingTest` for more details.