def ensure_server(data)
      if @servers.include?(data['id'].to_i)
        @servers[data['id'].to_i]
      else
        @servers[data['id'].to_i] = Server.new(data, self)
      end
    end
def ensure_server(data)
      if @servers.include?(data['id'].to_i)
        @servers[data['id'].to_i]
      else
        @servers[data['id'].to_i] = Server.new(data, self)
      end
    end
Ensures a given server object is cached and if not, cache it from the given data hash.
 @param data [Hash] A data hash representing a server.
 @return [Server] the server represented by the data hash.