code: def setup_method(self):
      self.X = np.random.randn(50, 3)
      self.y = np.random.randn(50)
      self.Xnew = np.random.randn(60, 3)
      self.noise = pm.gp.cov.WhiteNoise(0.1)
      self.covs = (
          pm.gp.cov.ExpQuad(3, [0.1, 0.2, 0.3]),
          pm.gp.cov.ExpQuad(3, [0.1, 0.2, 0.3]),
          pm.gp.cov.ExpQuad(3, [0.1, 0.2, 0.3]),
      )
      self.means = (
          pm.gp.mean.Constant(0.5),
          pm.gp.mean.Constant(0.5),
          pm.gp.mean.Constant(0.5),
      )
  
imports: from functools import reduce
  from operator import add
  import numpy
  import numpy.testing
  import pytest
  import pymc
  from pymc.math import cartesian
label_desc: Use image node_id 1 for calling the TestGPAdditive obj's underlying member method code with example usage: obj.setup_method() without return types