====== models/person.js =====
import DS from 'ember-data';

export default DS.Model.extend({

  some attributes and stuff

});

====== models/man.js =====

import DS from 'ember-data';
import Person from 'person';

export default Person.extend({

  some attributes and stuff

});


====== tests/models/man-test.js =====

import {
  moduleForModel,
  test
} from 'ember-qunit';

moduleForModel('man', 'Man', {
  // Specify the other units that are required for this test.
  needs: ['model:person']
});

test('it exists', function() {
  var model = this.subject();
  // var store = this.store();
  ok(!!model);
});