docs: public void putMap(Map<String, String> map)
      {
          if (map == null) {
              putNumber1(0);
          }
          else {
              Utils.checkArgument(map.size() < 256, "Map has to be smaller than 256 elements");
              putNumber1(map.size());
              for (Entry<String, String> entry : map.entrySet()) {
                  if (entry.getKey().contains("=")) {
                      throw new IllegalArgumentException("Keys cannot contain '=' sign. " + entry);
                  }
                  if (entry.getValue().contains("=")) {
                      throw new IllegalArgumentException("Values cannot contain '=' sign. " + entry);
                  }
                  String val = entry.getKey() + "=" + entry.getValue();
                  putString(val);
              }
          }
      }