def +(to_add)
      if StackableFlash.stacking

        if to_add.kind_of?(Array)
          super(to_add)
        else

          # Make sure it responds to +, otherwise just push it onto the stack
          if self.last.respond_to?(:+)
            self[self.length - 1] = self.last + to_add
          else
            self << to_add
          end
        end

      else
        super(to_add)
      end
    end
def +(to_add)
      if StackableFlash.stacking

        if to_add.kind_of?(Array)
          super(to_add)
        else

          # Make sure it responds to +, otherwise just push it onto the stack
          if self.last.respond_to?(:+)
            self[self.length - 1] = self.last + to_add
          else
            self << to_add
          end
        end

      else
        super(to_add)
      end
    end
TODO: Add smart filters for flashes, like 'sticky' via method_missing.
 Handle the following use case:
   flash[:notice] = 'First Part'
   flash[:notice] += ' Second Part'
 => ['First Part Second Part']