code: def test_epsg():
      """Unit test for loading EPSG to Proj4 string dictionary."""
  
      assert et.epsg["4326"] == "+proj=longlat +datum=WGS84 +no_defs"
  
file_path: earthpy/earthpy/tests/test_epsg.py
imports: import pytest
  import rasterio
  import os.path
  import earthpy
  import earthpy.spatial
  from earthpy.io import path_to_example
label_desc: Use image node_id 2 for calling a global function with example usage: test_epsg() without return types