Evil localisation of $_ ?

gistfile1.pl

sub _format_key {
    my $class = shift;
    my ( $key ) = @_;

    # Localise $_ so we can use functions that operate on $_ for berevity
    local $_    = $key;
    # Convert to the correct format/case
    s/publishDate/publish_date/ if /publishDate/;
    s/lastModifiedDate/last_modified_date/ if /lastModifiedDate/;

    return $_;
}