code: def test_concat_axis0_crs(self):
      # CRS not set for both GeoDataFrame
      res = pd.concat([self.gdf, self.gdf])
      self._check_metadata(res)
  
      # CRS set for both GeoDataFrame, same CRS
      res1 = pd.concat(
          [self.gdf.set_crs("epsg:4326"), self.gdf.set_crs("epsg:4326")]
      )
      self._check_metadata(res1, crs="epsg:4326")
  
      # CRS not set for one GeoDataFrame, but set for the other GeoDataFrame
      with pytest.warns(
          UserWarning,
          match=r"CRS not set for some of the concatenation inputs.*",
      ):
          res2 = pd.concat([self.gdf, self.gdf.set_crs("epsg:4326")])
          self._check_metadata(res2, crs="epsg:4326")
  
      # CRS set for both GeoDataFrame, different CRS
      with pytest.raises(
          ValueError,
          match=r"Cannot determine common CRS for concatenation inputs.*",
      ):
          pd.concat(
              [
                  self.gdf.set_crs("epsg:4326"),
                  self.gdf.set_crs("epsg:4327"),
              ]
          )
  
      # CRS not set for one GeoDataFrame, but set for the other GeoDataFrames,
      # same CRS
      with pytest.warns(
          UserWarning,
          match=r"CRS not set for some of the concatenation inputs.*",
      ):
          res3 = pd.concat(
              [
                  self.gdf,
                  self.gdf.set_crs("epsg:4326"),
                  self.gdf.set_crs("epsg:4326"),
              ]
          )
          self._check_metadata(res3, crs="epsg:4326")
  
      # CRS not set for one GeoDataFrame, but set for the other GeoDataFrames,
      # different CRS
      with pytest.raises(
          ValueError,
          match=r"Cannot determine common CRS for concatenation inputs.*",
      ):
          pd.concat(
              [
                  self.gdf,
                  self.gdf.set_crs("epsg:4326"),
                  self.gdf.set_crs("epsg:4327"),
              ]
          )
  
file_path: geopandas/geopandas/tests/test_merge.py
imports: import warnings
  import pandas
  import pyproj
  import pytest
  from geopandas._compat import PANDAS_GE_21
  from geopandas.testing import assert_geodataframe_equal
  from pandas.testing import assert_index_equal
  from shapely.geometry import Point
  from geopandas import GeoDataFrame, GeoSeries
label_desc: Use image node_id 5 for calling the TestMerging obj's underlying member method code with example usage: obj.test_concat_axis0_crs() without return types