# File lib/twitter/core_ext/hash.rb, line 23
  def merge_user!(user_id_or_screen_name)
    case user_id_or_screen_name
    when Integer
      self[:user_id] = user_id_or_screen_name
    when String
      self[:screen_name] = user_id_or_screen_name
    end
    self
  end