public static void appendComment(Program program, Address address, CommentType commentType,
			String prefix, String comment, String sep) {
		if (comment == null || comment.isBlank()) {
			return;
		}
		CodeUnit cu = getCodeUnitForComment(program, address);
		if (cu != null) {
			String existingComment = cu.getComment(commentType);
			if (existingComment != null && existingComment.contains(comment)) {
				// don't add same comment twice
				return;
			}
		}
		AppendCommentCmd cmd = new AppendCommentCmd(address, commentType,
			Objects.requireNonNullElse(prefix, "") + comment, sep);
		cmd.applyTo(program);
	}
Append a string to a description of a field in a structure.

@param dtc the {@link DataTypeComponent field} in a struct
@param description string to append, if null or empty nothing happens.
@param sep characters to place after previous description to separate it from the
new portion.
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DWARFUtil.java