# File lib/aws/core/lazy_error_classes.rb, line 68
      def const_missing constant
        const_missing_mutex.synchronize do
          # It's possible the constant was defined by another thread while
          # this thread was waiting on the mutex, check before setting.
          if error_const_set?(constant)
            const_get(constant)
          else
            const_set(constant, Class.new(Errors::Base) { extend LazyErrorClasses })
          end
        end
      end