code: @SneakyThrows
     public static List<String> split(CharSequence input, char separator) {
        if (input == null) {
           return new ArrayList<>();
        }
        Preconditions.checkArgument(separator != '"', "Separator cannot be a quote");
        try (CSVReader reader = CSV.builder().delimiter(separator).reader(new StringReader(input.toString()))) {
           List<String> all = new ArrayList<>();
           List<String> row;
           while ((row = reader.nextRow()) != null) {
              all.addAll(row);
           }
           return all;
        }
     }
docs: Properly splits a delimited separated string.
  
  @param input     The input
  @param separator The separator
  @return A list of all the cells in the input