code: def version_variants(version):
      
  
      result = [version]
  
      # Add trailing ".0" as needed to ensure that we have at least
      # major.minor.patch
      parts = version.split(".")
      while len(parts) < 3:
          parts.append("0")
          result.append(".".join(parts))
  
      return result
docs: Given an igraph version number, returns a list of possible version
      number variants to try when looking for a suitable nightly build of the
      C core to download from igraph.org.