Filter "target" in subject dont work correct

(I used a translator, sorry..)

The "target" argument in the "subject" filter parameter does not work correctly
The attached screenshot shows a code that assumes the following work:
If the mob has a tag and if its target is from the "player" family, then it writes two messages to the chat:
1)  Is " True" - that is, the conditions were successful
2)  Is "I - target" message from the target

But!
If the mob doesn't have target, then "True" is still sent to the chat
Although why, if there is haven't target, as well as his family in general

Further:
If the mob has a target, then both messages will be successfully sent to the chat
Regardless of the family, although "player" is specified in the filter

Steps to Reproduce:

1.  Create event for mob, with code:

   "filters": {"test": "is_family", "subject": "target", "value": "illager"},
   "sequence": [
   {"run_command": {"command": ["say I have target"]}},
   {"run_command": {"command": ["say Is target"],"target":"target"}}
   ]
   

1. Spawn mob, with code
2. Trigger event with mob (can use command /event)
3. Spawn another mob that can be target of first mob
4. Trigger event with first mob one more time

Observed Results:
If mob hasn't target, then Mob say "I have target".
If mob has target, then Mob say "I have target" and despite the filter conditions target of Mob will say "Is target"

Expected Results:
If mob hasn't target, then nothing should happen
If mob has target, then Mob say "I have target" and if family of target is illager, then target of Mob will say "Is target"