code: public static function EVEN($number)
      {
          $number = Functions::flattenSingleValue($number);
  
          if ($number === null) {
              return 0;
          } elseif (is_bool($number)) {
              $number = (int) $number;
          }
  
          if (is_numeric($number)) {
              $significance = 2 * self::SIGN($number);
  
              return (int) self::CEILING($number, $significance);
          }
  
          return Functions::VALUE();
      }
docs: EVEN.
  
  Returns number rounded up to the nearest even integer.
  You can use this function for processing items that come in twos. For example,
  a packing crate accepts rows of one or two items. The crate is full when
  the number of items, rounded up to the nearest two, matches the crate's
  capacity.
  
  Excel Function:
  EVEN(number)
  
  @category Mathematical and Trigonometric Functions
  
  @param float $number Number to round
  
  @return int Rounded Number