docs: def do_rm(self, line):
          "rm [:tablename] [!fieldname:expectedvalue] [-v] {haskkey [rangekey]}"
          table, line = self.get_table_params(line)
          expected, line = self.get_expected(line)
  
          args = self.getargs(line)
  
          if "-v" in args:
              ret = "ALL_OLD"
              args.remove("-v")
          else:
              ret = None
  
          hkey = self.get_typed_key_value(table, args[0], True)
          rkey = self.get_typed_key_value(table, args[1], False) if len(args) > 1 else None
  
          item = table.new_item(hash_key=hkey, range_key=rkey)
          item = item.delete(expected_value=expected, return_values=ret)
          self.pprint(item)
  
          if self.consumed:
              print "consumed units:", item.consumed_units