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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def CheckIfUserIsAdmin(self, username):
 """Checks whether the user is an admin."""


    user_obj = data_store.REL_DB.ReadGRRUser(username)
    if user_obj.user_type != user_obj.UserType.USER_TYPE_ADMIN:
      raise access_control.UnauthorizedAccess("User %s is not an admin." %
                                              username)