1fn main() -> Result<(), std::io::Error> {2 let abi = <contract::Flipper as ink_lang::GenerateAbi>::generate_abi();3 let contents = serde_json::to_string_pretty(&abi)?;4 std::fs::create_dir("target").ok();5 std::fs::write("target/metadata.json", contents)?;6 Ok(())7}