code: public Set<String> getCommonPropertyAsSet(String key) {
  		Set<String> propertiesSet = new HashSet<>();
  		StringTokenizer tk = new StringTokenizer(props.getProperty(PropertiesBundleConstant.PROPS_PREFIX + key, ""),
  				",");
  		while (tk.hasMoreTokens())
  			propertiesSet.add(tk.nextToken().trim());
  		return propertiesSet;
  	}
docs: Returns as a set, the comma separated values of a property
  
  @param key
  the key of the property
  @return a set of the comma separated values of a property