```ruby
module Royce
  module Methods

    # Called when module included in a class
    # includer == User
    # includer.class == Class
    def self.included includer
      # With instance eval, we can add instance methods
      # Add instance methods like user? admin?
      includer.instance_eval do

        # Loop through all available role names
        # and add a name? method that queries the has_role? method
        available_role_names.each do |name|
          define_method("#{name}?") do
            has_role? name
          end
        end

      end
    end


    # These methods are included in all User instances

    def add_role name
      if allowed_role? name
        role = Role.find_or_create_by(name: name.to_s)
        roles << role
      end
    end

    def remove_role name
      if allowed_role? name
        role = Role.find_by(name: name.to_s)
        roles.delete role
      end
    end

    def has_role? name
      # grab each role name and check for inclusion
      roles.pluck(:name).include?(name.to_s)
    end

    def allowed_role? name
      self.class.available_role_names.include? name.to_s
    end

    def role_list
      roles.pluck(:name)
    end

  end
end
```

Use exists? to test for presence of a role.
user
```ruby
module Royce
  module Methods

    # Called when module included in a class
    # includer == User
    # includer.class == Class
    def self.included includer
      # With instance eval, we can add instance methods
      # Add instance methods like user? admin?
      includer.instance_eval do

        # Loop through all available role names
        # and add a name? method that queries the has_role? method
        available_role_names.each do |name|
          define_method("#{name}?") do
            has_role? name
          end
        end

      end
    end


    # These methods are included in all User instances

    def add_role name
      if allowed_role? name
        role = Role.find_or_create_by(name: name.to_s)
        roles << role
      end
    end

    def remove_role name
      if allowed_role? name
        role = Role.find_by(name: name.to_s)
        roles.delete role
      end
    end

    def has_role? name
      # grab each role name and check for inclusion
      roles.exists?(name: name.to_s)
    end

    def allowed_role? name
      self.class.available_role_names.include? name.to_s
    end

    def role_list
      roles.pluck(:name)
    end

  end
end
```
assistant