Function validate_agent_joining

pub fn validate_agent_joining(
    _agent_pub_key: HoloHash<Agent>,
    _membrane_proof: &Option<Arc<SerializedBytes>>,
) -> Result<ValidateCallbackResult, WasmError>

Validation the network performs when you try to join, you can’t perform this validation yourself as you are not a member yet. There is access to network calls in this function