docs: def byte_str(nBytes, unit='bytes', precision=2):
      """
      representing the number of bytes with the chosen unit
  
      Returns:
          str
      """
      #return (nBytes * ureg.byte).to(unit.upper())
      if unit.lower().startswith('b'):
          nUnit = nBytes
      elif unit.lower().startswith('k'):
          nUnit =  nBytes / (2.0 ** 10)
      elif unit.lower().startswith('m'):
          nUnit =  nBytes / (2.0 ** 20)
      elif unit.lower().startswith('g'):
          nUnit = nBytes / (2.0 ** 30)
      elif unit.lower().startswith('t'):
          nUnit = nBytes / (2.0 ** 40)
      else:
          raise NotImplementedError('unknown nBytes=%r unit=%r' % (nBytes, unit))
      return repr2(nUnit, precision=precision) + ' ' + unit