package Parent_object;
    
    sub new {
        my $O = bless {}, shift;
        
        $O->{'attribute-1'} = "value 1";
        $O->{'attribute-2'} = "value 2";
        $O->{'attribute-3'} = "value 3";
        [...]
        
        return ($O);
    }

##</code><code>##

    package Parent_object;
    
    sub new {
        my $O = bless {}, shift;
        
        $O->{'data'} = _fill_attributes (@_);
        
        return ($O);
    }
    
    sub _fill_attributes {
        my $result = {};
        
        $result->{'attribute-1'} = $_[0];
        $result->{'attribute-2'} = $_[1];
        $result->{'attribute-3'} = $_[2];
        [....]
        
        return ($result);
    }

##</code><code>##

    package Parent_object;
    
    [...]
    
    sub do_something {
        my $O = shift;
        
        my $f = $O->{'sub-function-for-this-case'};
        $f->($O);
        
        return ([whatever]);
    }

##</code><code>##

    package Parent_object;
    
    [...]
    
    sub do_something {
        my $O = shift;
        
        my $f = $O->{'sub-function-for-this-case'};
        $f->($O->{'data'});
        
        return ([whatever]);
    }