// In lock_pool()
let bonding_curve_remaining_lamports = ctx.accounts.bonding_curve_sol_escrow.get_lamports();
let sol_ix = system_instruction::transfer(
    &ctx.accounts.bonding_curve_sol_escrow.to_account_info().key,
    &ctx.accounts.fee_receiver.to_account_info().key,
    bonding_curve_remaining_lamports,
);
let remaining_lamports = ctx.accounts.bonding_curve_sol_escrow.get_lamports();
require!(
    remaining_lamports == ctx.accounts.global.migrate_fee_amount,
    ContractError::InvalidRemainingBalance
);
