code: def addVariables(self, variables, domain):
          
          for variable in variables:
              self.addVariable(variable, domain)
docs: Add one or more variables to the problem
  
          Example:
  
          >>> problem = Problem()
          >>> problem.addVariables(["a", "b"], [1, 2, 3])
          >>> solutions = problem.getSolutions()
          >>> len(solutions)
          9
          >>> {'a': 3, 'b': 1} in solutions
          True
  
          @param variables: Any object containing a sequence of objects
                            represeting problem variables
          @type  variables: sequence of hashable objects
          @param domain: Set of items defining the possible values that
                         the given variables may assume
          @type  domain: list, tuple, or instance of C{Domain}