@Nullable
  private PsiElement resolvePositionalFormat(@NotNull PyArgumentList argumentList) {
    int n = 0;
    boolean notSureAboutStarArgs = false;
    PyStarArgument firstStarArg = null;
    for (PyExpression arg : argumentList.getArguments()) {
      final PyStarArgument starArg = PyUtil.as(arg, PyStarArgument.class);
      if (starArg != null) {
        if (!starArg.isKeyword()) {
          if (firstStarArg == null) {
            firstStarArg = starArg;
          }
          // TODO: Support multiple *args for Python 3.5+
          final Ref<PyExpression> resolvedRef = resolvePositionalStarExpression(starArg, n);
          if (resolvedRef != null) {
            final PsiElement resolved = resolvedRef.get();
            if (resolved != null) {
              return resolved;
            }
          }
          else {
            notSureAboutStarArgs = true;
          }
        }
      }
      else if (!(arg instanceof PyKeywordArgument)) {
        if (myPosition == n) {
          return arg;
        }
        n++;
      }
    }
    return notSureAboutStarArgs ? firstStarArg : null;
  }
@Nullable
  private PsiElement resolvePositionalFormat(@NotNull PyArgumentList argumentList)