public static ObjectNode normalizeKeys(final ObjectNode objectNode) {
    return normalizeKeys(objectNode, Predicates.alwaysTrue());
  }
Converts all the object keys (but none of the string values) to lowercase for easier lookup.
This is useful in cases such as the 'genesis.json' file where all keys are assumed to be case
insensitive.

@param objectNode The ObjectNode to be normalized
@return a copy of the json object with all keys in lower case.
config/src/main/java/org/hyperledger/besu/config/JsonUtil.java