docs: def is_available(self, rtdc_ds, verbose=False):
          """Check whether the feature is available
  
          Parameters
          ----------
          rtdc_ds: instance of RTDCBase
              The dataset to check availability for
  
          Returns
          -------
          available: bool
              `True`, if feature can be computed with `compute`
  
          Notes
          -----
          This method returns `False` for a feature if there
          is a feature defined with the same name but with
          higher priority (even if the feature would be
          available otherwise).
          """
          # Check config keys
          for item in self.req_config:
              section, keys = item
              if section not in rtdc_ds.config:
                  if verbose:
                      print("{} not in config".format(section))
                  return False
              else:
                  for key in keys:
                      if key not in rtdc_ds.config[section]:
                          if verbose:
                              print("{} not in config['{}']".format(key,
                                                                    section))
                          return False
          # Check features
          for col in self.req_features:
              if col not in rtdc_ds:
                  return False
          # Check priorities of other features
          for of in AncillaryFeature.features:
              if of == self:
                  # nothing to compare
                  continue
              elif of.feature_name == self.feature_name:
                  # same feature name
                  if of.priority <= self.priority:
                      # lower priority, ignore
                      continue
                  else:
                      # higher priority
                      if of.is_available(rtdc_ds):
                          # higher priority is available, thus
                          # this feature is not available
                          return False
                      else:
                          # higher priority not available
                          continue
              else:
                  # other feature
                  continue
          return True