fn add_message(
env: soroban_sdk::Env,
author: soroban_sdk::String,
message: soroban_sdk::String,
) -> soroban_sdk::String
fn get_messages(env: soroban_sdk::Env) -> soroban_sdk::Vec
fn like_message(env: soroban_sdk::Env, id: u64) -> soroban_sdk::String
fn message_count(env: soroban_sdk::Env) -> u32
fn delete_message(env: soroban_sdk::Env, id: u64) -> soroban_sdk::String