or download this
package LWP::UserAgent::Powerfull;
use LWP::UserAgent::Proxified;
...
push @LWP::UserAgent::Determined::ISA, "LWP::UserAgent::Proxified";
push @LWP::UserAgent::Cached::ISA, "LWP::UserAgent::Determined";
our @ISA = "LWP::UserAgent::Cached";