如果是真的要你去作证,根据法律,你还必须去,否则后果比较严重。
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If you were a victim of a crime or witness to one, you may receive a subpoena telling you when you have to come to court, and who is calling you to court. The Crown prosecutor or defense lawyer will probably talk to you to find out what you know about the case before they decide to call you as a witness. At this stage you do not have to answer their questions unless you want to; but if either lawyer subpoenas you as a witness, you must go to court.
If you receive a subpoena, you should arrange for time off work and for someone to look after your children while you are in court. Your employer must give you time off to go to court, and can't fire you or penalize you for the time off, but is not required to pay you. It is hard to say how long you will be in court. A legal proceeding could take hours or days; and you could be required to go to court more than once. You must be available to the court until the judge lets you leave. If you don't go to court when you are supposed to, the judge can charge you with contempt of court and issue a warrant for your arrest....."