@Override
        public String lookup(@NonNull final String key) {
            final String output = System.getProperty(key);
            if (output == null) {
                LOGGER.log(
                        Level.WARNING,
                        String.format(
                                "Configuration import: System Properties did not contain the specified key '%s'. Will default to empty string.",
                                key));
                return "";
            }
            return output;
        }
Resolve string with potential secrets

@param toInterpolate potential variables that need to revealed
@return original string with any secrets that could be resolved if secrets could not be
resolved they will be defaulted to default value defined by ':-', otherwise default to empty
String. Secrets are defined as anything enclosed by '${}'
plugin/src/main/java/io/jenkins/plugins/casc/SecretSourceResolver.java