src/Filter/RangeFilter.php
public function getQuery(string $startKey, string $endKey): array
    {
        return [
            $startKey => $this->start ? $this->start->getTimestamp() : null,
            $endKey   => $this->end ? $this->end->getTimestamp() : null,
        ];
    }
public function getQuery(string $startKey, string $endKey): array
    {
        return [
            $startKey => $this->start ? $this->start->getTimestamp() : null,
            $endKey   => $this->end ? $this->end->getTimestamp() : null,
        ];
    }
@param string $startKey
@param string $endKey

@return array