code: def call(self, args, devnull=False):
          
          if self.debug:
              click.echo(subprocess.list2cmdline(args))
              click.confirm('Continue?', default=True, abort=True)
          try:
              kwargs = {}
              if devnull:
                  # Pipe to /dev/null (or equivalent).
                  kwargs['stderr'] = subprocess.STDOUT
                  kwargs['stdout'] = self.FNULL
              ret_code = subprocess.call(args, **kwargs)
          except subprocess.CalledProcessError:
              return False
          return ret_code
docs: Call other processes.
          args - list of command args
          devnull - whether to pipe stdout to /dev/null (or equivalent)