sub my_sub {
	my $self   = shift;
	my $params = shift;

	my $foo = $params->{'foo'};
	my $bar = $params->{'bar'};

}

# and in another child we could have
sub my_sub {
	my $self   = shift;
	my $params = shift;

	my $foo = $params->{'foo'};
	my $bork = $params->{'bork'};
}

# and the parent calls them like
$child->my_sub({'foo' => $foo,
                'bar' => $bar,
                'baz' => $baz,
                'bork' => $bork});