createEstimate()
getEstimates()
Estimate subject is an object that has invoices (contact or estimate)
createEstimate() : \Moneybird\Estimate
\Moneybird\Estimate
getEstimates(\Moneybird\Estimate_Service $service, string $filter) : \Moneybird\Estimate_Array
\Moneybird\Estimate_Service
string
\Moneybird\Estimate_Array