public function getData()
 {
     switch ($this->operator) {
         case TES4BinaryExpressionOperator::OPERATOR_ADD():
             return $this->leftValue->getData() + $this->rightValue->getData();
         case TES4BinaryExpressionOperator::OPERATOR_DIVIDE():
             return $this->leftValue->getData() / $this->rightValue->getData();
         case TES4BinaryExpressionOperator::OPERATOR_MULTIPLY():
             return $this->leftValue->getData() * $this->rightValue->getData();
         case TES4BinaryExpressionOperator::OPERATOR_SUBSTRACT():
             return $this->leftValue->getData() - $this->rightValue->getData();
     }
     throw new ConversionException("Unknown TES4BinaryExpressionOperator");
 }