code: def test_marginal_split__get_marginal_layers():
      marginal = " hist:t,dens:tr ,  dens:b:.1,\n\tbox :\n\ttblr  "
      marginals = _get_marginal_layers(
          **_get_marginal_layers_props(marginal=marginal)
      )
      assert 12 == len(marginals)
      for marginal_layer in marginals:
          spec_dict = marginal_layer.as_dict()
          assert spec_dict["marginal"]
          assert spec_dict["margin_side"] in ["t", "b", "l", "r"]
          if "margin_size" in spec_dict:
              assert isinstance(spec_dict["margin_size"], float)
  
file_path: lets-plot/python-package/test/plot/test_bistro_common.py
imports: import pytest
  from lets_plot.bistro._plot2d_common import _get_bin_params_2d, _get_geom2d_layer, _get_marginal_layers
label_desc: Use image node_id 11 for calling a global function with example usage: test_marginal_split__get_marginal_layers() without return types