my @fields = REQUIRED_FIELDS;
    for my $e (@$a) {
        for my $i (0..$#fields) {
            if ($e eq $fields[$i]) {
                $href->{$e} = 0;
                splice @fields, $i, 1;
                last;
            }
        }
    }

##</code><code>##

    my %fields = map { $_ => 1 } REQUIRED_FIELDS;
    for my $e (@$a) {
        $href->{$e} = 0
            if $fields{$e};
    }