code: def munmap(self, start, size):
          
          for addr in range(start, start + size):
              if len(self._symbols) == 0:
                  break
              if addr in self._symbols:
                  del self._symbols[addr]
          super().munmap(start, size)
docs: Deletes the mappings for the specified address range and causes further
          references to addresses within the range to generate invalid memory
          references.
  
          :param start: the starting address to delete.
          :param size: the length of the unmapping.