code: public static function fromArrayDefinition($operator, $operands)
      {
          if (!isset($operands[0], $operands[1])) {
              throw new InvalidArgumentException("Operator '$operator' requires two operands.");
          }
  
          return new static($operands[0], $operator, $operands[1]);
      }
docs: {@inheritdoc}
  @throws InvalidArgumentException if wrong number of operands have been given.