code: public HashMap getProperties(String propertyGroup) {
  		HashMap props = new HashMap();
  		
  		for (Map.Entry<String, Object> entry : properties.entrySet()) {
  			String key = entry.getKey();
  			Object value = entry.getValue();
  			if (key.startsWith(propertyGroup)) {
  				props.put(key, value);
  			}
  		}
  
  		return props;
  	}
docs: Get a group of properties.
  
  @param propertyGroup The group name to obtain.
  @return Properties object with requested values.