access to WirelessPhy since 802_15_4

[jgpeoc]

I'm using Phy/WirelessPhy/802_15_4 in my simulation and I have created a agent in c++ but I don't know how to access to the physic layer since c++, I have tried to access using something like this WirelessPhy* wphy_ = (WirelessPhy*) (node_->ifhead()).lh_first but get an error.