code: def update(self, data):
      super().update(data)
      if len(self.shape) > 2:
          raise ValueError(
              "Expect the target data for {name} to have shape "
              "(batch_size, num_classes), "
              "but got {shape}.".format(
                  name=self.name, shape=self.shape
              )
          )
      if len(self.shape) > 1 and self.shape[1] > 1:
          return
      self.labels = self.labels.union(set(np.unique(data.numpy())))
  
file_path: autokeras/autokeras/analysers/output_analysers.py
imports: import numpy
  from autokeras.engine import analyser
label_desc: Use image node_id 2 for calling the ClassificationAnalyser obj's underlying member method code with example usage: obj.update(data) without return types