<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">This is common when you are using façade design pattern. You use a façade to flatten and hide the internal composition of a composite object and present it as a single flat object. In some types of projects this comes up rather frequently. Both in client / UI programming and server side / business logic.<div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On May 25, 2017, at 11:34 AM, Xiaodi Wu via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class=""><span class="Apple-converted-space"> </span>Is it actually very common? In what sort of programming?</span></div></blockquote></div><br class=""></div></body></html>