new {
	my ($class, $conf_file) = @_;
	my $opts = read_conf( $conf_file );
	$opts->{model_trainer} = eval sprintf q{ require %s;
                                             \&%s::train },  
                                          ($opts->{model}) x 2;
	# ... validation ...
	bless $opts, $class;
}

sub train {
	my $self = shift;
	my $data = voodoo( shift );
	$self->{model_trainer}->( $self, $data );
}