presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/PushSampleIntoTableScan.java/PushSampleIntoTableScan/getSamplingType
class PushSampleIntoTableScan:    private static SampleType getSamplingType(Type sampleNodeType)
    {
        switch (sampleNodeType) {
            case SYSTEM:
                return SampleType.SYSTEM;
            case BERNOULLI:
                return SampleType.BERNOULLI;
            default:
                throw new UnsupportedOperationException("Not yet implemented for " + sampleNodeType);
        }
    }