Constructs the genealogy graph used by the model.
//the greatgrandparent generation
Person a1 = new Person("Jack (great-granddaddy)");
Person a2 = new Person("Jean (great-granny)");
Person a3 = new Person("Albert (great-granddaddy)");
Person a4 = new Person("Rae (great-granny)");
Person a5 = new Person("Paul (great-granddaddy)");
Person a6 = new Person("Josie (great-granny)");
//the grandparent generation
Person b1 = new Person("Peter (grandpa)");
Person b2 = new Person("Zoe (grandma)");
Person b3 = new Person("Simon (grandpa)");
Person b4 = new Person("James (grandpa)");
Person b5 = new Person("Bertha (grandma)");
Person b6 = new Person("Veronica (grandma)");
Person b7 = new Person("Anne (grandma)");
Person b8 = new Person("Renee (grandma)");
Person b9 = new Person("Joseph (grandpa)");
//the parent generation
Person c1 = new Person("Isabelle (mom)");
Person c2 = new Person("Frank (dad)");
Person c3 = new Person("Louis (dad)");
Person c4 = new Person("Laurence (dad)");
Person c5 = new Person("Valerie (mom)");
Person c6 = new Person("Marie (mom)");
Person c7 = new Person("Helen (mom)");
Person c8 = new Person("Mark (dad)");
Person c9 = new Person("Oliver (dad)");
//the youngest generation
Person d1 = new Person("Clement (boy)");
Person d2 = new Person("Colin (boy)");
Person.linkFamily(a1,a2,new Person[] {b1,b2,b3,b4});
Person.linkFamily(a3,a4,new Person[] {b5,b6,b7});
Person.linkFamily(a5,a6,new Person[] {b8,b9});
Person.linkFamily(b3,b6,new Person[] {c1,c2,c3});
Person.linkFamily(b4,b5,new Person[] {c4,c5,c6});
Person.linkFamily(b8,b7,new Person[] {c7,c8,c9});
Person.linkFamily(c4,c7,new Person[] {d1,d2});
return a1;