def validate_mandatory_attributes
      invalid = missing_mandatory_attributes
      unless invalid.empty? then
        logger.error("Validation of #{qp} unsuccessful - missing #{invalid.join(', ')}:\n#{dump}")
        raise ValidationError.new("Required attribute value missing for #{self}: #{invalid.join(', ')}")
      end
      validate_owner
    end
def validate_mandatory_attributes
      invalid = missing_mandatory_attributes
      unless invalid.empty? then
        logger.error("Validation of #{qp} unsuccessful - missing #{invalid.join(', ')}:\n#{dump}")
        raise ValidationError.new("Required attribute value missing for #{self}: #{invalid.join(', ')}")
      end
      validate_owner
    end
Validates that this domain object contains a non-nil value for each mandatory attribute.

 @raise [ValidationError] if a mandatory attribute value is missing