In June $2018$ the IAASB approved ISA $540($Revised$),$ Auditing Accounting Estimates and Related Disclosures, as a final standard. The standard came into effect for all audits on periods beginning on or after $15$th December $2021.$

$1.$ What changes were introduced in ISA $540($Revised $2019)$ regarding the audit of accounting estimates? $(4$ marks$)$