code: def test_holoviews_defined_default_opts(self, df, backend):
      hv.opts.defaults(
          hv.opts.Scatter(height=400, width=900, show_grid=True)
      )
      plot = df.hvplot.scatter("x", "y", c="category")
      opts = Store.lookup_options(backend, plot, "plot")
      # legend_position shouldn't apply only to bokeh
      if backend == "bokeh":
          assert opts.kwargs["legend_position"] == "right"
      assert opts.kwargs["show_grid"] is True
      assert opts.kwargs["height"] == 400
      assert opts.kwargs["width"] == 900
  
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 12 for calling the TestOptions obj's underlying member method code with example usage: obj.test_holoviews_defined_default_opts(df, backend) without return types