old_contents: from setuptools import setup
  from rust_ext import build_rust_cmdclass, install_lib_including_rust, \
      develop_including_rust
  
  setup(name='hello-rust',
      version='1.0',
      cmdclass={
          # This enables 'setup.py build_rust', and makes it run
          # 'cargo extensions/cargo.toml' before building your package.
          'build_rust': build_rust_cmdclass('extensions/Cargo.toml', 
                                            ext_name="hello_rust.hellorust"),
          # This causes your rust binary to be automatically installed
          # with the package when install_lib runs (including when you 
          # run 'setup.py install'.
          'install_lib': install_lib_including_rust,
          # This supports development mode for your rust extension by 
          # causing the ext to be built in-place, according to its ext_name
          'develop': develop_including_rust
      },
      packages=['hello_rust'],
      # rust extensions are not zip safe, just like C-extensions.
      zip_safe=False
  )
  
new_contents: from setuptools import setup
  from rust_ext import build_rust_cmdclass, install_lib_including_rust, \
      develop_including_rust
  
  setup(name='hello-rust',
      version='1.0',
      cmdclass={
          # This enables 'setup.py build_rust', and makes it run
          # 'cargo extensions/cargo.toml' before building your package.
          'build_rust': build_rust_cmdclass('extensions/Cargo.toml', 
                                            ext_name="hello_rust.helloworld"),
          # This causes your rust binary to be automatically installed
          # with the package when install_lib runs (including when you 
          # run 'setup.py install'.
          'install_lib': install_lib_including_rust,
          # This supports development mode for your rust extension by 
          # causing the ext to be built in-place, according to its ext_name
          'develop': develop_including_rust
      },
      packages=['hello_rust'],
      # rust extensions are not zip safe, just like C-extensions.
      zip_safe=False
  )
  
subject: fix example's package name