private function removeDuplicates(array $pairs, array $pair): array
    {
        if (!in_array($pair, $pairs, true)) {
            $pairs[] = $pair;
        }

        return $pairs;
    }
private function removeDuplicates(array $pairs, array $pair): array
    {
        if (!in_array($pair, $pairs, true)) {
            $pairs[] = $pair;
        }

        return $pairs;
    }
private function removeDuplicates ( array $ pairs , array $ pair ) : array { if ( ! in_array ( $ pair , $ pairs , true ) ) { $ pairs [ ] = $ pair ; } return $ pairs ; }
Adds a query pair only if it is not already present in a given array.
Adds a query pair only if it is not already present in a given array .