use Params::Validate qw (validate_with);
sub example_method {
   my $self = shift;
   my %args = validate_with (
             params         => \@_,
             spec           => {
                        thing  => 1,
                        handle => 1 },
             normalize_keys => sub {
                               return lc($_[0]);
                                },
             );

    my ($handle, $thing) = @args{'handle','thing'};
    #...
}