code: def test_fit_invalid_2d():
      # C=None and stim_radius=None here, cannot define C
      i2 = InvertedEncoding2D(
          stim_xlim=xlim,
          stim_ylim=ylim,
          stimulus_resolution=res,
          stim_radius=None,
      )
      i2.define_basis_functions_sqgrid(nchannels=[12, 6])
      with pytest.raises(ValueError):
          i2.fit(Xd, yd)
  
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 14 for calling a global function with example usage: test_fit_invalid_2d() without return types