code: def generate(self, state):
          
          if self.count >= random.randint(DharmaConst.VARIABLE_MIN, DharmaConst.VARIABLE_MAX):
              return "%s%d" % (self.var, random.randint(1, self.count))
          var = random.choice(self)
          prefix = self.eval(var[0], state)
          suffix = self.eval(var[1], state)
          self.count += 1
          element_name = "%s%d" % (self.var, self.count)
          self.default += "%s%s%s\n" % (prefix, element_name, suffix)
          return element_name
docs: Return a random variable if any, otherwise create a new default variable.