the command "bitcoin-cli getblockstats 0000000000000000000c61ff8f761ce509fc8901d3c22d61fec89637042ea2ba" does not work.

It displays "error: Error parsing JSON:0000000000000000000c61ff8f761ce509fc8901d3c22d61fec89637042ea2ba"

but it should display the block stats like the documentation says.

also bitcoin-cli getblockstats 0 does not work. block number must be at least 1 to work. But blocks start at 0.

tested with 0.20.1 on freebsd, another user on IRC acknowledged the problem.
: m_tx_results{ {wtxid, result} } {}
};
/**
 * Try to add a transaction to the mempool. This is an internal function and is exposed only for testing.
 * Client code should use ChainstateManager::ProcessTransaction()
 *
 * @param[in]  active_chainstate  Reference to the active chainstate.
 * @param[in]  tx                 The transaction to submit for mempool acceptance.
 * @param[in]  accept_time        The timestamp for adding the transaction to the mempool.
 *                                It is also used to determine when the entry expires.
 * @param[in]  bypass_limits      When true, don't enforce mempool fee and capacity limits.
 * @param[in]  test_accept        When true, run validation checks but don't submit to mempool.
 *
 * @returns a MempoolAcceptResult indicating whether the transaction was accepted/rejected with reason.
 */
MempoolAcceptResult AcceptToMemoryPool(Chainstate& active_chainstate, const CTransactionRef& tx,
                                       int64_t accept_time, bool bypass_limits, bool test_accept)
    EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/**
* Validate (and maybe submit) a package to the mempool. See doc/policy/packages.md for full details
* on package validation rules.
* @param[in]    test_accept     When true, run validation checks but don't submit to mempool.
* @returns a PackageMempoolAcceptResult which includes a MempoolAcceptResult for each transaction.
* If a transaction fails, validation will exit early and some results may be missing. It is also
* possible for the package to be partially submitted.
*/
PackageMempoolAcceptResult ProcessNewPackage(Chainstate& active_chainstate, CTxMemPool& pool,
                                                   const Package& txns, bool test_accept)
                                                   EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/**