class TestCase::ComplexCalc {
  static method add : TestCase::Complex_2d ($z1 : TestCase::Complex_2d, $z2 : TestCase::Complex_2d) {
    my $z3 : TestCase::Complex_2d;
    
    $z3->{re} = $z1->{re} + $z2->{re};
    $z3->{im} = $z1->{im} + $z2->{im};
    
    return $z3;
  }
}