sub introduce {
    my($self)=$_[0];
    print "Hello, I'm ";
#    $self->tellName();
    tellName( $self );
}

##</code><code>##

Hello, I'm Alice.

Hi, I'm Billy The Kid.
Here's my mom: Hello, I'm Alice.

##</code><code>##

package child;
sub tellName  {
    my($self)=$_[0];
    if ( caller eq __PACKAGE__ ) {
        print "$self->{'nickName'}.\n";
    }
    else {
        $self->SUPER::tellName();
    }
}