code: Properties getProperties(String prefix, boolean removePrefix) {
  		Properties result = new Properties();
  		for (String key : getPropertyNames()) {
  			if (key.startsWith(prefix)) {
  				result.put((removePrefix) ? key.substring(prefix.length()) : key, getProperty(key));
  			}
  		}
  		return result;
  	}
docs: Gets all properties with a key starting with prefix.
  
  @param prefix
  @param removePrefix
  remove prefix in the resulting properties or not
  @return properties starting with prefix