code: private String getText(JsonNode node, String propertyName) {
          JsonNode childNode = node.get(propertyName);
          if (childNode == null) {
              return null;
          }
          return childNode.asText();
      }
docs: Get the text from child node with the given name.  Returns null if child node does not exist.
  
  @param node         Node to search
  @param propertyName Name of the child node
  @return The text value of the child node