Consider It Done

Consider It Done
I don't understand the phrase "Consider It Done" (is that correct?) I heard it from vdogame call of duty 2

I would greatly appreciate it if someone could tell me the meaning Thank you.
and sorry my english is bad

If you ask me to do this, it is as good as done. It is so certain to be done, that you can already consider it as done. "Your wish is my command" is in the same vein of eagerness to please. SS