docs: def available(self, context):
          """Determine if this actions is available in this `context`.
  
          :param context: a dict whose content is left to application needs; if
                          :attr:`.condition` is a callable it receives `context`
                          in parameter.
          """
          if not self._enabled:
              return False
          try:
              return self.pre_condition(context) and self._check_condition(context)
          except Exception:
              return False