code: public static void put(Writer writer, Character value) throws IOException {
  		if (value == null) {
  			writer.write("null");
  		} else {
  			writer.write("\"");
  			writer.write(sanitize(value));
  			writer.write("\"");
  		}
  	}
docs: Writes the given value with the given writer, sanitizing with {@link #sanitize(String)} as a valid JSON-formatted data.
  @param writer
  @param value
  @throws IOException
  @author vvakame