I'm new to Odoo and I feel lost. How to understand the flow of execution after I press some button (any button, validate SO, print order, etc etc). I'm using the debugger so I'm looking for a spot where I can set the breakpoint and then step down line-by-line to see what it does, which methods are invoked and such. (In PHP I would put it at some root controller)

For example, I'm in delivery order, print order button. In debug mode I see that when I click that button the method name is do_print_picking defined as :

@api.multi
def do_print_picking(self):
    self.write({'printed': True})
    return self.env["report"].get_action(self, 'stock.report_picking')

So how do I go from here, what does the last line really call?