public Comment addReactionCountsEntry(String key, Integer value) {
        if (null == this.reactionCounts) {
            this.reactionCounts = new java.util.HashMap<String, Integer>();
        }
        if (this.reactionCounts.containsKey(key))
            throw new IllegalArgumentException("Duplicated keys (" + key.toString() + ") are provided.");
        this.reactionCounts.put(key, value);
        return this;
    }
Add a single ReactionCounts entry

@see Comment#withReactionCounts
@returns a reference to this object so that method calls can be chained together.
aws-java-sdk-codecommit/src/main/java/com/amazonaws/services/codecommit/model/Comment.java