CheckPushResult pushes the specified txn and checks that the pushee's resolution is the expected one.

StrToCPutExistingValue takes a string that was written using, say, a Put and returns the bytes that can be passed to a Batch.CPut() as the expected value resulting from said Put.

DontExpectAnything means we're not going to check the state in which the pusher found the pushee's txn record.

ExpectAborted means that the pushee is expected to have been aborted.

ExpectCommitted means that the pushee is expected to have found the pushee to be committed - or STAGING in which case the push will have performed successful transaction recovery.

ExpectPusheeTxnRecordNotFound means we're expecting the push to not find the pushee txn record.

ExpectPusheeTxnRecovery means we're expecting transaction recovery to be performed (after finding a STAGING txn record).

ExpectedTxnResolution expresses an expectation for CheckPushResult about the outcome of the push.

PushExpectation expresses an expectation for CheckPushResult about what the push did.