Cannot use array parameters for 'on' field

[AlexisNeveu]

Describe the bug

When trying to pass the trigger actions via an array directly in the 'on' field it is impossible to draw the model.

To Reproduce

Steps to reproduce the behavior:

1. Go to the text view
2. Copy the code from the 1st screenshot below
3. Click on 'Draw'
4. See error

Expected behavior
Should draw the model as well as if it was written in the third screenshot.

Screenshots

Application (please complete the following information):

• leto-modelizer commit hash 280a6e5ffd4bcb75bc8e3c8d4e20c787ea067222
• githubator-plugin commit hash b02edb8

Desktop (please complete the following information):

• OS: Ubuntu
• Browser FireFox