Function load_program_with_pubkey 

pub fn load_program_with_pubkey<CB: TransactionProcessingCallback>(
    callbacks: &CB,
    environments: &ProgramRuntimeEnvironments,
    pubkey: &Pubkey,
    slot: Slot,
    execute_timings: &mut ExecuteTimings,
    reload: bool,
) -> Option<Arc<ProgramCacheEntry>>

👎Deprecated since 3.1.0: This crate has been marked for formal inclusion in the Agave Unstable API. From v4.0.0 onward, the agave-unstable-api crate feature must be specified to acknowledge use of an interface that may break without warning.

Loads the program with the given pubkey.

If the account doesn’t exist it returns None. If the account does exist, it must be a program account (belong to one of the program loaders). Returns Some(InvalidAccountData) if the program account is Closed, contains invalid data or any of the programdata accounts are invalid.