code: public static Set<String> convertDataToSet(final Object data) {
  		if (data == null) {
  			return null;
  		} else if (data instanceof Collection) {
  			Collection items = (Collection) data;
  			Set<String> set = new HashSet<>();
  			for (Object item : items) {
  				if (item != null) {
  					set.add(item.toString());
  				}
  			}
  			return set;
  		} else if (data instanceof Object[]) {
  			Object[] items = (Object[]) data;
  			Set<String> set = new HashSet<>();
  			for (Object item : items) {
  				if (item != null) {
  					set.add(item.toString());
  				}
  			}
  			return set;
  		} else {
  			Set<String> set = new HashSet<>();
  			set.add(data.toString());
  			return set;
  		}
  	}
docs: Convert the data to a set (if necessary).
  <p>
  Removes null items in the conversion.
  </p>
  
  @param data the data to convert to a set
  @return the data converted to a set