private Properties loadPropertiesFromURL(URL url, boolean secure) {
    Properties result = new Properties();
    loadPropertiesFromURL(result, url);
    if (!result.isEmpty()) {
      setSource(result, ConfigSource.file(url.toString(), secure));
    }
    return result;
  }
For every key in p mark it as being from the given source.
geode-core/src/main/java/org/apache/geode/distributed/internal/DistributionConfigImpl.java