in maven-wrapper/src/main/java/org/apache/maven/wrapper/cli/CommandLineParser.java [213:229]
private static String join(Collection<?> things, String separator) {
StringBuffer buffer = new StringBuffer();
boolean first = true;
if (separator == null) {
separator = "";
}
for (Object thing : things) {
if (!first) {
buffer.append(separator);
}
buffer.append(thing.toString());
first = false;
}
return buffer.toString();
}