code: def test_marker_dim(self, df, kind, backend):
      plot = df.hvplot("x", "y", marker="category", kind=kind)
      opts = Store.lookup_options(backend, plot, "style")
      assert opts.kwargs["marker"] == "category"
      assert "category" in plot.vdims
  
imports: import hvplot
  import holoviews
  import numpy
  import pandas
  import pytest
  import xarray
  from holoviews import Store
  from holoviews.core.options import Options, OptionTree
label_desc: Use image node_id 7 for calling the TestOptions obj's underlying member method code with example usage: obj.test_marker_dim(df, kind, backend) without return types