presto-main/src/main/java/io/prestosql/operator/SpatialJoinOperator.java/SpatialJoinOperator/addInput
class SpatialJoinOperator:    @Override
    public void addInput(Page page)
    {
        verify(probe == null);
        probe = page;
        probePosition = 0;

        joinPositions = null;
    }