How to use the pep517.envbuild.BuildEnvironment function in pep517

"""))

            # Copy the pyproject.toml:
            shutil.copyfile(
                os.path.join(path, 'pyproject.toml'),
                os.path.join(output_path, 'pyproject.toml')
            )

            # Get build backend and requirements from pyproject.toml:
            with open(os.path.join(path, 'pyproject.toml')) as f:
                build_sys = pytoml.load(f)['build-system']
                backend = build_sys["build-backend"]
                build_requires.extend(build_sys["requires"])

            # Get a virtualenv with build requirements and get all metadata:
            env = BuildEnvironment()
            metadata = None
            with env:
                hooks = Pep517HookCaller(path, backend)
                env.pip_install([transform_dep_for_pip(req) for req in build_requires])
                reqs = hooks.get_requires_for_build_wheel({})
                env.pip_install([transform_dep_for_pip(req) for req in reqs])
                try:
                    metadata = hooks.prepare_metadata_for_build_wheel(path)
                except Exception:  # sadly, pep517 has no good error here
                    pass
            if metadata is not None:
                metadata_path = os.path.join(
                    path, metadata, "METADATA"
                )
        else:
            # This is a wheel, so metadata should be in *.dist-info folder: