sub AUTOLOAD
 {
   my ($self, $field ) = @_ ;
   (my $sub = $AUTOLOAD) =~ s/.*::// ; 
   return (exists($self->{'data'}->{$sub}) ? $self->{'data'}->{$sub} : undef) ;
 }

##</code><code>##

my @public_fields = qw(address phone);

sub in_array {
 ...
}

sub AUTOLOAD
 {
   my ($self, $field ) = @_ ;
   (my $sub = $AUTOLOAD) =~ s/.*::// ; 
   return (in_array(\@public_fields,$sub) && exists($self->{'data'}->{$sub}) ? $self->{'data'}->{$sub} : undef) ;
 }