code: def _isna(this):
      """isna version that works for both scalars and (Geo)Series"""
      with warnings.catch_warnings():
          # GeoSeries.isna will raise a warning about no longer returning True
          # for empty geometries. This helper is used below always in combination
          # with an is_empty check to preserve behaviour, and thus we ignore the
          # warning here to avoid it bubbling up to the user
          warnings.filterwarnings(
              "ignore",
              r"GeoSeries.isna\(\) previously returned",
              UserWarning,
          )
          if hasattr(this, "isna"):
              return this.isna()
          elif hasattr(this, "isnull"):
              return this.isnull()
          else:
              return pd.isnull(this)
  
file_path: geopandas/geopandas/testing.py
imports: import warnings
  import pandas
  from geopandas import GeoDataFrame, GeoSeries
  from geopandas.array import GeometryDtype
label_desc: Use image node_id 1 for calling a global function with example usage: _isna(this) and returns: this, this, pd