def has_variable?(var)
      @stack.reverse_each do |scope|
        if SCOPE_BLOCKER_9000 == scope
          return false
        elsif scope.include?(var)
          return true
        end
      end
    end
def has_variable?(var)
      @stack.reverse_each do |scope|
        if SCOPE_BLOCKER_9000 == scope
          return false
        elsif scope.include?(var)
          return true
        end
      end
    end
Checks if the given variable is in scope.