code: def test_get_backend():
      context = chainerx.Context()
  
      backend = context.get_backend("native")
      assert backend.name == "native"
  
      assert context.get_backend("native") is backend
  
      with pytest.raises(chainerx.BackendError):
          context.get_backend("something_that_does_not_exist")
  
file_path: chainer/tests/chainerx_tests/unit_tests/test_context.py
imports: import pytest
  import chainerx
label_desc: Use image node_id 3 for calling a global function with example usage: test_get_backend() without return types