while ( ... ) {
    my $cat = $$methods{'category'};
    my $class = 'Category::' . $category{$cat}->[0];
    eval "use $class;"
    die $@ if $@;
}
while ( ... ) {
    my $cat = $$methods{'category'};
    my $class = 'Category::' . $category{$cat}->[0];
    my $method = $category{$cat}->[1];
    eval "$class->new()->$method(\$key, \$params, \$testCase)";
    die $@ if $@;
}