You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: keyset.rb
    path of file: ./repos/gitlabhq/lib/gitlab/pagination
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Gitlab
  module Pagination
    module Keyset
      SUPPORTED_TYPES = %w[
        Project
      ].freeze

      def self.ava
    
      def self.available?(request_context, relation)
        order_by = request_context.page.order_by

        return false unless available_for_type?(relation)
        return false unless order_by.size == 1 && order_by[:id]

        true
      end