Testing for LAS files with zero points

I was loading a set of LAS files to process through the RASTERDEMGENERATOR transformer and kept receiving an error which would stop my workbench "Either all points are linear or initial set of points did not consist of 3 non NAN elevations". After scouring the log file I noticed some of the las files being read contained no points. Once I manually identified those las files the processing went on with out a hitch. My question is how can I test incoming LAS files so they will filter out files with no points in them?