public static Collector<CharSequence, ?, String> toCsv(String eol) {
		if (eol.isEmpty()) {
			throw new IllegalArgumentException("EOL must not be empty.");
		}
		for (int i = 0; i < eol.length(); ++i) {
			if (!isLineBreak(eol.charAt(i))) {
				throw new IllegalArgumentException(
					"EOl contains non-linebreak char: '%s'.".formatted(eol)
				);
			}
		}

		return Collectors.joining(eol, "", eol);
	}
Return a collector for joining a list of CSV rows into one CSV string.
For the line breaks, the given {@code eol} sequence is used.

@param eol the end of line sequence used for line breaks
@return a collector for joining a list of CSV rows into one CSV string
jenetics.ext/src/main/java/io/jenetics/ext/util/CsvSupport.java