Add empty for PointBuffer.
Add empty for PointBuffer.

mpgerlek/PDAL-old,mtCarto/PDAL,radiantbluetechnologies/PDAL,Sciumo/PDAL,jwomeara/PDAL,jwomeara/PDAL,radiantbluetechnologies/PDAL,jwomeara/PDAL,radiantbluetechnologies/PDAL,mtCarto/PDAL,boundlessgeo/PDAL,DougFirErickson/PDAL,lucadelu/PDAL,DougFirErickson/PDAL,mpgerlek/PDAL-old,Sciumo/PDAL,lucadelu/PDAL,lucadelu/PDAL,boundlessgeo/PDAL,DougFirErickson/PDAL,boundlessgeo/PDAL,Sciumo/PDAL,mtCarto/PDAL,radiantbluetechnologies/PDAL,Sciumo/PDAL,mpgerlek/PDAL-old,mtCarto/PDAL,boundlessgeo/PDAL,lucadelu/PDAL,DougFirErickson/PDAL,mpgerlek/PDAL-old,jwomeara/PDAL