code: def unpack(self, source: IO):
          
          field_count = unpack('>H', source.read(2))[0]
          for _ in repeat(None, field_count):
              field = Field(self._cf)
              field.unpack(source)
              self.append(field)
docs: Read the FieldTable from the file-like object `source`.
  
          .. note::
  
              Advanced usage only. You will typically never need to call this
              method as it will be called for you when loading a ClassFile.
  
          :param source: Any file-like object providing `read()`