void removeLeadingEmptyRows() {
		Iterator<ValidatableLine> iterator = iterator();
		for (; iterator.hasNext();) {
			ValidatableLine line = iterator.next();
			if (line instanceof PlaceHolderLine) {
				iterator.remove();
			}
			else {
				return; // stop at the first real line
			}
		}
	}
A class that holds lines that will be used to generate diffs.  It also has a reference to 
the source of the data so that it can create the correct type of empty lines as needed.
Ghidra/Features/Base/src/main/java/ghidra/app/util/html/diff/DiffLines.java