```ruby
require 'rails_helper'
require 'support/privacy_example'
require 'support/public_scope_example'

RSpec.describe Character, type: :model do
  it_behaves_like 'content with privacy'
  it_behaves_like 'content with an is_public scope'
  it { is_expected.to validate_presence_of(:name) }
end
```

Add deletion test for sibling relation
user
```ruby
require 'rails_helper'
require 'support/privacy_example'
require 'support/public_scope_example'

RSpec.describe Character, type: :model do
  it_behaves_like 'content with privacy'
  it_behaves_like 'content with an is_public scope'
  it { is_expected.to validate_presence_of(:name) }

  context "when character having a sibling is deleted" do
    before do
      @alice = create(:character, name: "Alice")
      @bob = create(:character, name: "Bob")
      @alice.siblings << @bob
      @alice.destroy()
    end

    it "don't delete the sibling" do
      expect(Character.exists?(@bob.id)).to be true
    end

    it "delete sibling relation" do
      expect(@alice.siblings.include?(@bob)).to be false
    end

    it "delete reverse sibling relation" do
      expect(@bob.siblings.include?(@alice)).to be false
    end
  end
end
```
assistant