You can populate the database with the example schema using the following GQL INSERT statement:
INSERT
(albus:Wizard {name: "Albus", level: 95, affinity: "Light"}),
(severus:Wizard {name: "Severus", level: 80, affinity: "Dark"}),
(harry:Wizard {name: "Harry", level: 45, affinity: "Light"}),
(hermione:Wizard {name: "Hermione", level: 50, affinity: "Light"}),
(ron:Wizard {name: "Ron", level: 30, affinity: "Earth"}),
(luna:Wizard {name: "Luna", level: 40, affinity: "Air"}),
(draco:Wizard {name: "Draco", level: 45, affinity: "Dark"}),
(fireball:Spell {name: "Fireball", element: "Fire", base_damage: 50}),
(frostbolt:Spell {name: "Frostbolt", element: "Ice", base_damage: 45}),
(shield_light:Spell {name: "Shield of Light", element: "Light", base_damage: 0}),
(shadow_curse:Spell {name: "Shadow Curse", element: "Dark", base_damage: 75}),
(albus)-[:Knows]->(severus),
(harry)-[:Knows]->(hermione),
(harry)-[:Knows]->(ron),
(ron)-[:Knows]->(luna),
(severus)-[:Knows]->(draco),
(albus)-[:AlliedWith {mana_cost: 5, affinity_boost: 10}]->(harry),
(harry)-[:AlliedWith {mana_cost: 10, affinity_boost: 5}]->(hermione),
(hermione)-[:AlliedWith {mana_cost: 15, affinity_boost: 8}]->(ron),
(ron)-[:AlliedWith {mana_cost: 8, affinity_boost: 3}]->(luna),
(draco)-[:AlliedWith {mana_cost: 12, affinity_boost: 6}]->(severus),
(albus)-[:Teaches {experience_required: 500}]->(shield_light),
(severus)-[:Teaches {experience_required: 400}]->(shadow_curse),
(hermione)-[:Teaches {experience_required: 200}]->(fireball),
(harry)-[:Teaches {experience_required: 150}]->(frostbolt)