sub Func1 {
    do we have a num_var;
    do we have a name_var;
    do we have params (optional)

    is the num_var of number format
    is the name_var of name format

    ....

    other code
}

Func1($num_var, $name_var, %params);

##</code><code>##

Func1 {
    is number of args correct?

    check arg1 is a number and only a number with reg exp?
    check arg2 is a string and only a string with reg exp?
    ...

    other code
}

##</code><code>##


sub CheckArgs {
    get number of args
    get args to check
    
    check we have the right number of args
    foreach arg check the type with the appropriate reg exp.

    return status.
}

sub Func1 {
    CheckArgs (2, @_, "NUM", "STRING");

    ....

    other code
}
sub Func2 {
    CheckArgs (3, @_, "STRING", "NUM", "STRING");

    ....

    other code
}

##</code><code>##

sub add_output {
	#Create an unconnected named output
        my $self = shift;
	my $graph = $self->{graph};
	my $name = shift;
	my %params = @_;

	#Check for valid options
	foreach my $p ( keys %params ) {
		if ( !exists $valid_userconfigurable_vertex_params->{$p} ) {
			Carp::confess(sprintf "Unknown Option : $p");
		}
	}

	#Set the activation function
	my $activation;
	if ( exists $params{activation} ) {
		$activation = $params{activation};
	} else {
		$activation = "SIGMOID";
	}

	#Create the vertex
        $graph->set_vertex_attributes($name, {  id => GetNewVertexNumber($self),
						added_a_vertex => 1,
                                                allow_inputs => "Yes",
                                                allow_outputs => "No",
                                                activation => $activation,
                                                value => 0 });

	#Connect vertex to the bias vertex
	$graph->add_edge("BIAS", $name);

	#An update to the layout is required
	$graph->set_graph_attribute("update_layout", 1);
}