code: def _setup(self):
      space_2 = GraphSpace(2)
      metric = space_2.metric
  
      metric.set_aligner(ExhaustiveAligner())
  
      metric.set_point_to_geodesic_aligner(
          "default", s_min=-1.0, s_max=1.0, n_points=10
      )
  
      metrics = [metric] * 3
      estimators = [_AACRegression(metric) for metric in metrics]
  
      estimators[1].init_point = gs.zeros((2, 2))
      input_dim = [1, 1, 2]
  
      self.data_generators = [
          _TrivialRegressionData(input_dim, metrics, estimators)
      ]
  
      self.basic_data_generators = [
          _TrivialData(_AACRegression, is_regression=True)
      ]
  
imports: import geomstats.backend
  from geomstats.geometry.stratified.graph_space import ExhaustiveAligner, GraphSpace, _GeodesicToPointAligner
  from geomstats.learning.aac import _AACGGPCA, _AACFrechetMean, _AACRegression
  from geomstats.test.data import TestData
  from geomstats.test.test_case import np_backend
label_desc: Use image node_id 1 for calling the AACRegressionTestData obj's underlying member method code with example usage: obj._setup() without return types