[How-to] How to allow multiple copies of Totem to run

I searched for a solution to this problem for a long time and finally found :))
I do not argue that this method is the simplest.

So.
Go to the properties of the video file and add the following command to the list of applications with which you can open this type of file:


And then select the just created item from the list:


Having done this operation with each type of video file, we will be able to launch several copies of Totem simultaneously.