private static @Nullable Couple<PsiElement> getRelativeImportSourceRange(@NotNull PyFromImportStatement statement) {
    final PsiElement fromKeyword = statement.getFirstChild();
    assert fromKeyword.getNode().getElementType() == PyTokenTypes.FROM_KEYWORD;
    final PsiElement elementAfterFrom = PsiTreeUtil.skipWhitespacesForward(fromKeyword);
    if (elementAfterFrom == null) {
      return null;
    }
    else if (elementAfterFrom instanceof PyReferenceExpression) {
      return Couple.of(elementAfterFrom, elementAfterFrom);
    }
    else if (elementAfterFrom.getNode().getElementType() == PyTokenTypes.DOT) {
      PsiElement lastDot;
      PsiElement next = elementAfterFrom;
      do {
        lastDot = next;
        next = PsiTreeUtil.skipWhitespacesForward(next);
      }
      while (next != null && next.getNode().getElementType() == PyTokenTypes.DOT);
      if (next instanceof PyReferenceExpression) {
        return Couple.of(elementAfterFrom, next);
      }
      else {
        return Couple.of(elementAfterFrom, lastDot);
      }
    }
    return null;
  }
private static @Nullable Couple<PsiElement> getRelativeImportSourceRange(@NotNull PyFromImportStatement statement)