use namada_sdk::token::Amount;
use namada_sdk::signing::default_sign;
 
let alice_addr = sdk.wallet().await.find_address("alice".to_string())
  .expect("Invalid alias").into_owned();
let validator_addr = Address::from_str("tnam1qykv7yvcx8eyjld4kuumg0whwjq8usulwy7uhlsw")
  .expect("Invalid address");
 
// build the bond tx
let bond_tx_builder = sdk
  .new_bond(validator_addr, Amount::native_whole(100)) // whole amount, ie. 100 NAM
  .source(alice_addr)
  .signing_keys(vec![alice_acct.public_key.clone()]);
  
let (mut bond_tx, signing_data) = bond_tx_builder
  .build(&sdk)
  .await
  .expect("Unable to build bond tx");
 
// sign the tx
sdk.sign(&mut bond_tx, &bond_tx_builder.tx, signing_data, default_sign, ())
  .await
  .expect("unable to sign bond tx");
 
//submit to the chain
match sdk.submit(bond_tx, &bond_tx_builder.tx).await {
  Ok(res) => println!("Tx result: {:?}", res),
  Err(e) => println!("Tx error: {:?}", e) 
}