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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def build_wheel(wheel_directory, config_settings, metadata_directory=None):
 """Invoke the mandatory build_wheel hook. If a wheel was already built in the prepare_metadata_for_build_wheel fallback, this will copy it rather than rebuilding the wheel. """

    prebuilt_whl = _find_already_built_wheel(metadata_directory)
    if prebuilt_whl:
        shutil.copy2(prebuilt_whl, wheel_directory)
        return os.path.basename(prebuilt_whl)

    return _build_backend().build_wheel(wheel_directory, config_settings,
                                        metadata_directory)