public static String getValueAsString(
      final ObjectNode node, final String key, final String defaultValue) {
    return getValueAsString(node, key).orElse(defaultValue);
  }
Get the string representation of the value at {@code key}. For example, a numeric value like 5
will be returned as "5".

@param node The {@code ObjectNode} from which the value will be extracted.
@param key The key corresponding to the value to extract.
@param defaultValue The value to return if no value is found at {@code key}.
@return The value at the given key as a string if it exists, otherwise {@code defaultValue}
config/src/main/java/org/hyperledger/besu/config/JsonUtil.java