private void ensureReactionTypesIsMutable() {
        com.google.protobuf.Internal.IntList tmp = reactionTypes_;
        if (!tmp.isModifiable()) {
            reactionTypes_ = com.google.protobuf.GeneratedMessageLite.mutableCopy(tmp);
        }
    }
<code>repeated int32 reaction_types = 2;</code>

@param index The index of the element to return.
@return The reactionTypes at the given index.
turms-client-kotlin/src/main/java/im/turms/client/model/proto/request/message/DeleteMessageReactionsRequest.java