presto-main/src/main/java/io/prestosql/operator/scalar/ArrayCardinalityFunction.java/ArrayCardinalityFunction/arrayCardinality
class ArrayCardinalityFunction:    @TypeParameter("E")
    @SqlType(StandardTypes.BIGINT)
    public static long arrayCardinality(@SqlType("array(E)") Block block)
    {
        return block.getPositionCount();
    }