code: def test_rgb_single_channels():
      """Check assumptions about single channel R, G, and B images."""
      tif_names = [color + ".tif" for color in ["red", "green", "blue"]]
      fnames = [eio.path_to_example(f) for f in tif_names]
      rgb_parts = list()
      for f in fnames:
          with rio.open(f) as src:
              rgb_parts.append(src.read())
              assert str(src.crs) == rio.crs.CRS.from_epsg(4326)
  
      with rio.open(eio.path_to_example("rmnp-rgb.tif")) as src:
          assert np.array_equal(src.read(), np.concatenate(rgb_parts))
  
imports: import os
  import requests
  import pytest
  import numpy
  import rasterio
  import geopandas
  import earthpy.io
label_desc: Use image node_id 6 for calling a global function with example usage: test_rgb_single_channels() without return types