code: def df():
      return pd.DataFrame(
          [[1, 2, "A", 0.1], [3, 4, "B", 0.2], [5, 6, "C", 0.3]],
          columns=["x", "y", "category", "number"],
      )
  
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 4 for calling a global function with example usage: df() and returns: pd