docs: def register(self, module):
          """
          Function registers into self.commands from module.
  
          Args
          ----
            module (module): The module name.
          """
          if module is not None:
              cmds = self.retrieve_commands(module)
  
              for c in cmds:
                  if self.valid_name(c.name):
                      cmd = c(self.subparsers)
                      self.commands.append(cmd)
                  else:
                      print(colored("Warning: Command %s has empty name. It won't be registered"
                                    % c, 'yellow'))