in src/main/java/org/apache/commons/exec/util/MapUtils.java [71:80]
public static <K, V> Map<String, V> prefix(final Map<K, V> source, final String prefix) {
if (source == null) {
return null;
}
final Map<String, V> result = new HashMap<>();
for (final Map.Entry<K, V> entry : source.entrySet()) {
result.put(prefix + '.' + Objects.toString(entry.getKey(), ""), entry.getValue());
}
return result;
}