docs: def gen_wenner(self, a):
          """Generate Wenner measurement configurations.
  
          Parameters
          ----------
          a: int
              distance (in electrodes) between subsequent electrodes of each
              four-point configuration.
  
          Returns
          -------
          configs: Kx4 numpy.ndarray
              array holding the configurations
          """
          configs = []
          for i in range(1, self.nr_electrodes - 3 * a + 1):
              configs.append(
                  (i, i + a, i + 2 * a, i + 3 * a),
              )
          configs = np.array(configs)
          self.add_to_configs(configs)
          return configs