code: def _parse_versions(versions):
      
      if isinstance(versions, compat.basestring):
          versions = versions.split(',')
      return [VersionSpecifier.from_version_string(v) for v in versions]
docs: Parse multiple versions as read from disk. The versions value may be any
      one of:
          - a single version string ('>0.12.1')
          - a single string specifying multiple comma-separated versions
              ('>0.11.1,<=0.12.2')
          - an array of single-version strings (['>0.11.1', '<=0.12.2'])
  
      Regardless, this will return a list of VersionSpecifiers