code: def test_2d_custom_channels():
      nchan = 8
      res = 10
      npix = res * res
      channels = np.random.rand(nchan, npix) * 2 - 1
      bds = [-1, 1]
      s = InvertedEncoding2D(
          stim_xlim=bds,
          stim_ylim=bds,
          stimulus_resolution=res,
          chan_xlim=bds,
          chan_ylim=bds,
          channels=channels,
      )
      assert s, "Unable to define custom InvertedEncoding2D channels"
  
imports: import pytest
  import numpy
  import logging
  from brainiak.reconstruct.iem import InvertedEncoding1D, InvertedEncoding2D
  from brainiak.utils.fmrisim import generate_1d_gaussian_rfs, generate_1d_rf_responses
  from scipy.stats import circmean
label_desc: Use image node_id 6 for calling a global function with example usage: test_2d_custom_channels() without return types