code: public ValidationPlanResult append(Collection<ValidationResult> results) {
  		if (results == null) {
  			return this;
  		}
  		for (ValidationResult message : results) {
  			addResult(message);
  		}
  		return this;
  	}
docs: Appends a collection of validation message to the result.
  
  @param results a collection of validation messages to be added
  @return a reference to this object