docs: def convert(b):
      '''
      takes a number of bytes as an argument and returns the most suitable human
      readable unit conversion.
      '''
      if b > 1024**3:
          hr = round(b/1024**3)
          unit = "GB"
      elif b > 1024**2:
          hr = round(b/1024**2)
          unit = "MB"
      else:
          hr = round(b/1024)
          unit = "KB"
      return hr, unit