"weight" not used?

[iniwap]

"iaf_psc_exp/iaf_psc_exp_g/iaf_psc_exp_hc" all these update dont use "weight"?But in nest，
V_.weighted_spikes_ex_ = B_.spikes_ex_.get_value( lag );
V_.weighted_spikes_in_ = B_.spikes_in_.get_value( lag );
S_.i_syn_ex_ += V_.weighted_spikes_ex_;
S_.i_syn_in_ += V_.weighted_spikes_in_;

if not use ”weight“，then send/recv spike will be meaningless.Am I wrong, or is it not implemented?