docs: private String createKeyValue(String key, String value) {
          StringBuilder sb = new StringBuilder();
          // no quoting the key; "Keys are alphanumeric strings which may contain periods (.) and hyphens (-)"
          sb.append(key).append('=');
          if (value == null || value.isEmpty()) {
              return sb.append("\"\"").toString();
          }
  	StringBuilder valBuf = new StringBuilder();
  	boolean toBeQuoted = false;
          for (int i = 0; i < value.length(); ++i) {
              char c = value.charAt(i);
              switch (c) {
                  case '"':
                  case '\n':
                  case '\\':
                      // escape the character
                      valBuf.append('\\');
                  case ' ':
                      // space needs quotes, too
                      toBeQuoted = true;
                  default:
                      // always append
                      valBuf.append(c);
              }
          }
          if (toBeQuoted) {
              // need to keep quotes
              sb.append('"').append(valBuf.toString()).append('"');
          } else {
              sb.append(value);
          }
          return sb.toString();
      }