docs: def default(self, o):
          """
          JSONEncoder default method that converts NumPy arrays and quantities
          objects to lists.
          """
          if isinstance(o, Q_):
              return o.magnitude
          elif isinstance(o, np.ndarray):
              return o.tolist()
          else:
              # raise TypeError if not serializable
              return super(SimKitJSONEncoder, self).default(o)