drc-sim need gksu and it is not available what do i do ? (install using script)

[Abdalnablse10]

sudo apt-get install gksu

Reading package lists... Done Building dependency tree
Reading state information... Done Package gksu is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source

E: Package 'gksu' has no installation candidate