code: public Map<String,String> getMapFilter(String name) {
          String value = filters.get(name);
          if (value == null)
              return null;
          Map<String,String> map = new LinkedHashMap<>();
          if (value.startsWith("{") && value.endsWith("}")) {
              for (String entry : value.substring(1, value.length() - 1).split(",")) {
                  int eq = entry.indexOf('=');
                  if (eq > 0 && eq < entry.length() - 1) {
                      String key = entry.substring(0, eq).trim();
                      String val = entry.substring(eq + 1);
                      if ((val.startsWith("\"") && val.endsWith("\"")) || (val.startsWith("'") && val.endsWith("'")) && val.length() > 1) {
                          val = val.substring(1, val.length() - 1);
                      }
                      else {
                          val = val.trim();
                      }
                      map.put(key, val);
                  }
              }
          }
          return map.isEmpty() ? null : map;
      }
docs: Empty map returns null, as does invalid format.