presto-geospatial/src/main/java/io/prestosql/plugin/geospatial/GeoFunctions.java/GeoFunctions/getGeometrySlicesFromBlock
class GeoFunctions:    private static Iterable<Slice> getGeometrySlicesFromBlock(Block block)
    {
        requireNonNull(block, "block is null");
        return () -> new Iterator<Slice>()
        {
            private int iteratorPosition;

            @Override
            public boolean hasNext()
            {
                return iteratorPosition != block.getPositionCount();
            }

            @Override
            public Slice next()
            {
                if (!hasNext()) {
                    throw new NoSuchElementException("Slices have been consumed");
                }
                return GEOMETRY.getSlice(block, iteratorPosition++);
            }
        };
    }