code: def test_register_already_existing_typeset_fails():
      mytypeset = datashape.TypeSet(
          datashape.int64, datashape.float64, name="foo"
      )
      with pytest.raises(TypeError):
          datashape.typesets.register_typeset("foo", mytypeset)
  
file_path: datashader/datashader/datashape/tests/test_typeset.py
imports: from datashader import datashape
  import pytest
label_desc: Use image node_id 4 for calling a global function with example usage: test_register_already_existing_typeset_fails() without return types