final static void appendComment(Program program, Address address, String text,
			CommentType commentType) {

		String comment = program.getListing().getComment(commentType, address);
		if (comment != null) {
			if (comment.contains(text)) {
				return;
			}
			text = comment + "\n" + text;
		}

		SetCommentCmd.createComment(program, address, text, commentType);

	}
Append comment if not already present
@param program program
@param address listing address
@param text comment text
@param commentType comment type
Ghidra/Features/PDB/src/main/java/ghidra/app/util/bin/format/pdb/PdbUtil.java