def find_by_prefix(prefix)
      @machines.each do |uuid, data|
        return data.merge("id" => uuid) if uuid.start_with?(prefix)
      end

      nil
    end
def find_by_prefix(prefix)
      @machines.each do |uuid, data|
        return data.merge("id" => uuid) if uuid.start_with?(prefix)
      end

      nil
    end
Finds a machine where the UUID is prefixed by the given string.

 @return [Hash]