code: def test_stepsampler_regionslice(plot=False):
      np.random.seed(4)
      sampler = ReactiveNestedSampler(
          paramnames, loglike, transform=transform
      )
      sampler.stepsampler = RegionSliceSampler(nsteps=len(paramnames))
      r = sampler.run(log_interval=50, min_num_live_points=400)
      sampler.print_results()
      a = (np.abs(r["samples"] - 0.7) < 0.1).all(axis=1)
      b = (np.abs(r["samples"] - 0.3) < 0.1).all(axis=1)
      assert a.sum() > 1
      assert b.sum() > 1
  
imports: import numpy
  from ultranest.mlfriends import ScalingLayer, AffineLayer, MLFriends
  from ultranest import ReactiveNestedSampler
  from ultranest.stepsampler import RegionMHSampler, CubeMHSampler, CubeSliceSampler, RegionSliceSampler, SpeedVariableRegionSliceSampler, RegionBallSliceSampler
  from ultranest.stepsampler import generate_region_random_direction, ellipsoid_bracket, crop_bracket_at_unit_cube
  from ultranest.pathsampler import SamplingPathStepSampler
  from ultranest.stepsampler import select_random_livepoint, IslandPopulationRandomLivepointSelector
  from numpy.testing import assert_allclose
label_desc: Use image node_id 8 for calling a global function with example usage: test_stepsampler_regionslice(plot) without return types