$check->newrule(
   -name => 'myname',  #required, if no element specified, takes this.
   -element => ['one','two'],  #Takes arrayref or string
   -required => 0,      #required has no effect unless the data is omitted altogether.
   -tests => {
      -def => ['array','of','test','names'],
      -custom => [
         sub($$) : modifies { #code },
         sub(@) { #code },
      ],
   }
   );

#Or
$check->newrule(
   -name => 'myname',  #required, if no element specified, takes this.
   -element => ['one','two'],  #Takes arrayref or string
   -required => 0,      #required has no effect unless the data is omitted altogether.
   -tests => {
      -def => ['array','of','test','names'],
      -custom => [
         ctest(
            -args => 2,
            -mod => 1,
            -code => sub { #code },
            ),
         ctest(
            -args => '*',
            -code => sub { #code },
         ),
      ],
   }
   );