docs: private Integer getPortFromProjectOrSystemProperty(String var) {
          String sysProp = System.getProperty(var);
          if (sysProp != null) {
              return getAsIntOrNull(sysProp);
          }
          if (projProperties.containsKey(var)) {
              return getAsIntOrNull(projProperties.getProperty(var));
          }
          return null;
      }