docs: def _convert_size(self, size_str):
          """Convert units to GB"""
          suffix = size_str[-1]
          if suffix == 'K':
              multiplier = 1.0 / (1024.0 * 1024.0)
          elif suffix == 'M':
              multiplier = 1.0 / 1024.0
          elif suffix == 'T':
              multiplier = 1024.0
          else:
              multiplier = 1
  
          try:
              val = float(size_str.split(' ')[0])
              return val * multiplier
          except ValueError:
              return 0.0