code: def mock_fhs(tmpdir):
      """A fake FHS system"""
      tmpdir.ensure("share/gdal/header.dxf")
      tmpdir.ensure("share/proj/epsg")
      return tmpdir
  
imports: import pytest
  from rasterio._env import GDALDataFinder, PROJDataFinder, get_proj_data_search_paths, get_gdal_data
  from .conftest import gdal_version
label_desc: Use image node_id 2 for calling a global function with example usage: mock_fhs(tmpdir) and returns: tmpdir