class FakeFS::File::Stat

def readable?
  # a file is readable if, and only if, it has the following bits:
  #   4 ( read permission )
  #   5 ( read + execute permission )
  #   6 ( read + write permission )
  #   7 ( read + write + execute permission )
  # for each group we will isolate the wanted numbers ( for owner, world, or group )
  # and see if the third bit is set ( as that is the bit for read )
  read_bit = 4
  check_if_bit_set(read_bit)
end