public String toString(TimeRadix radix) {
		return steps.stream().map(s -> s.toString(radix)).collect(Collectors.joining(SEP));
	}
Construct (and normalize) a sequence formed by the steps in a followed by the steps in b

@param a the first sequence
@param b the second (appended) sequence
@return the resulting sequence
Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/model/time/schedule/Sequence.java