docs: public static void check(YamlNode node) {
          if (node instanceof YamlMapping) {
              for (YamlNameNodePair nodePair : ((YamlMapping) node).childrenPairs()) {
                  YamlNode child = nodePair.childNode();
                  if (child == null) {
                      String path = YamlUtil.constructPath(node, nodePair.nodeName());
                      reportNullEntryOnConcretePath(path);
                  }
  
                  check(nodePair.childNode());
  
              }
          } else if (node instanceof YamlSequence) {
              for (YamlNode child : ((YamlSequence) node).children()) {
                  if (child == null) {
                      throw new InvalidConfigurationException("There is a null configuration entry under sequence " + node.path()
                              + ". Please check if the provided YAML configuration is well-indented and no blocks started without "
                              + "sub-nodes.");
                  }
  
                  check(child);
              }
          } else {
              if (((YamlScalar) node).nodeValue() == null) {
                  reportNullEntryOnConcretePath(node.path());
              }
          }
      }