Function year_2023 

pub fn year_2023() -> Timestamp

Returns a Timestamp representation of the beginning of year 2023.

This is introduced to initialize StoreGenericTestContexts with the same latest timestamp by default. If two StoreGenericTestContext are initialized using Timestamp::now(), the second one will have a greater timestamp than the first one. So, the latest header of the second context cannot be submitted to first one. We can still set a custom timestamp via dummy_store_generic_test_context.