code: def test_stepsampler_regionmh(plot=False):
      np.random.seed(2)
      sampler = ReactiveNestedSampler(
          paramnames,
          loglike_vectorized,
          transform=transform,
          vectorized=True,
      )
      sampler.stepsampler = RegionMHSampler(nsteps=4 * 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, a
      assert b.sum() > 1, b
  
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 6 for calling a global function with example usage: test_stepsampler_regionmh(plot) without return types