docs: static public String format(Collection<?> collection, String property, String separator, boolean trim) {
  		StringBuilder sb = new StringBuilder();
  		if (collection != null){
  			for (Object o: collection){
  				Object p = null;
  				if (property == null){
  					p = o;
  				}else{
  					try {
  						p = PropertyUtils.getProperty(o, property);
  					} catch (Exception e) {
  						p = "ACCESS_ERROR:" + property;
  					}
  				}
  				sb.append(p == null? "null" : (trim? p.toString().trim() : p.toString()));
  				sb.append(separator);
  			}
  		}
  		if (sb.length() > 0){
  			sb.setLength(sb.length() - separator.length());
  		}
  		return sb.toString();
  	}