def mounted?
      return false unless respond_to?(:mounted)

      !mounted.nil? && !mounted.stdout.nil? && !mounted.stdout.empty?
    end
def mounted?
      return false unless respond_to?(:mounted)

      !mounted.nil? && !mounted.stdout.nil? && !mounted.stdout.empty?
    end
if the OS-specific file class supports inquirying as to whether the
 file/device is mounted, the #mounted method should return a command
 object whose stdout will not be nil if indeed the device is mounted.

 if the OS-specific file class does not support checking for mount
 status, the method should not be implemented and this method will
 return false.