src/Builder/Syntax/WhereWriter.php
protected function writeWhereIsNulls(Where $where, array &$whereArray)
    {
        $whereArray = \array_merge(
            $whereArray,
            $this->writeWhereIsNullable($where, 'getNull', 'writeIsNull')
        );
    }
protected function writeWhereIsNulls(Where $where, array &$whereArray)
    {
        $whereArray = \array_merge(
            $whereArray,
            $this->writeWhereIsNullable($where, 'getNull', 'writeIsNull')
        );
    }
@param Where $where
@param array $whereArray

@return array