text: CREATE EXTENSION IF NOT EXISTS check_digits;
  
  -- should be true
  select check_digits_ogrn('1037739010891');
  select check_digits_ogrn('304500116000157');
  
  -- should be false
  select check_digits_ogrn('302500116000353');
  
  -- should fail with error
  -- by length
  select check_digits_ogrn('30450011600015712');
  select check_digits_ogrn('10373901091');
  -- by wrong characters
  select check_digits_ogrn('1037739O10891');
  