'Opens the file of a command in transient mode, focuses and highlights
the region of the command'

def _open_transient(self, command):

    file_name = command.file_name
    v = self.window.open_file(file_name, sublime.TRANSIENT)
    run_after_loading(v, (lambda : self._add_highlight(v, command.region)))
    run_after_loading(v, (lambda : v.show(command.region)))
