void addPreComment(Address address, String preComment) {
		String existingPreComment = blockPreComments.get(address);
		preComment =
			(existingPreComment == null) ? preComment : existingPreComment + "\n" + preComment;
		blockPreComments.put(address, preComment);
	}
Manages the nesting of scoping blocks for functions and scoped variables.
Ghidra/Features/PDB/src/main/java/ghidra/app/util/pdb/pdbapplicator/BlockCommentsManager.java