`CashAndCashEquivalentsCashFlow` at beginning of the previous period MUST exist at least once.
`CashAndCashEquivalentsCashFlow` at end of period MUST be equal to `CashAndCashEquivalentsCashFlow` at beginning of period + `IncreaseDecreaseCashAndCashEquivalents` + `ChangesShortTermCashAndCashEquivalents`.