code: def set_version(package_name, version_str):
      
      current_version = get_version(package_name)
      version_file_path = helpers.package_file_path('_version.py', package_name)
      version_file_content = helpers.get_file_content(version_file_path)
      version_file_content = version_file_content.replace(current_version, version_str)
      with open(version_file_path, 'w') as version_file:
          version_file.write(version_file_content)
docs: Set the version in _version.py to version_str