code: def setup():
      rng = RandomState(1234)
      t = 1000
      resids = rng.standard_normal(t)
      return SetupInfo(
          rng=rng,
          t=t,
          resids=resids,
          resid_var=np.var(resids),
          sigma2=np.zeros_like(resids),
          backcast=1.0,
      )
  
imports: import types
  from typing import NamedTuple
  import warnings
  import numpy
  from numpy.random import RandomState
  from numpy.testing import assert_allclose, assert_almost_equal, assert_array_equal, assert_equal
  import pytest
  from scipy.special import gamma, gammaln
  from arch.univariate import ZeroMean
  from arch.univariate.distribution import Normal, SkewStudent, StudentsT
  import arch.univariate.recursions_python
  from arch.univariate.volatility import APARCH, ARCH, EGARCH, FIGARCH, GARCH, HARCH, ConstantVariance, EWMAVariance, FixedVariance, MIDASHyperbolic, RiskMetrics2006
  from arch.utility.exceptions import InitialValueWarning
label_desc: Use image node_id 1 for calling a global function with example usage: setup() and returns: SetupInfo