  The authors of the recent paper [1] boldly claim to discover a new fully
quantum approach to foundation of statistical mechanics: "Our conceptually
novel approach is free of mathematically ambiguous notions such as probability,
ensemble, randomness, etc."
  The aim of this note is to show that this approach is neither specific for
quantum systems nor really conceptually different from the standard textbook
arguments supporting microcanonical or canonical ensembles in statistical
mechanics.
