code: def step_impl07(context, len_list):
      
      assert len(context.fuzzed_string_list) == len_list
      for fuzzed_string in context.fuzzed_string_list:
          assert len(context.seed) == len(fuzzed_string)
          count = number_of_modified_bytes(context.seed, fuzzed_string)
          assert count >= 0
docs: Check assertions.
  
      :param len_list: expected number of variants.
      :param context: test context.