def assert(assertion, desc = nil)
      if assertion
        pass
      else
        what = if block_given?
          yield
        else
          "Failed assert: assertion was "\
          "`#{Assert::U.show(assertion, __assert_config__)}`."
        end
        fail(fail_message(desc, what))
      end
    end
def assert(assertion, desc = nil)
      if assertion
        pass
      else
        what = if block_given?
          yield
        else
          "Failed assert: assertion was "\
          "`#{Assert::U.show(assertion, __assert_config__)}`."
        end
        fail(fail_message(desc, what))
      end
    end
check if the assertion is a truthy value, if so create a new pass result,
 otherwise create a new fail result with the desc and what failed msg.
 all other assertion helpers use this one in the end