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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 populate_readme( version, circleci_build, appveyor_build, coveralls_build, travis_build ):
 """Populates ``README.rst`` with release-specific data. This is because ``README.rst`` is used on PyPI. Args: version (str):
 The current version. circleci_build (Union[str, int]):
 The CircleCI build ID corresponding to the release. appveyor_build (str):
 The AppVeyor build ID corresponding to the release. coveralls_build (Union[str, int]):
 The Coveralls.io build ID corresponding to the release. travis_build (int):
 The Travis CI build ID corresponding to the release. """

    with open(RELEASE_README_FILE, "r") as file_obj:
        template = file_obj.read()
    contents = template.format(
        version=version,
        circleci_build=circleci_build,
        appveyor_build=appveyor_build,
        coveralls_build=coveralls_build,
        travis_build=travis_build,
    )
    with open(README_FILE, "w") as file_obj:
        file_obj.write(contents)