Simplified empty contents checks in HtmlElement
Simplified empty contents checks in HtmlElement

thephpleague/commonmark,kkiernan/commonmark,fesor/commonmark,fesor/commonmark,thephpleague/commonmark,hason/commonmark,bcremer/commonmark,stof/commonmark,postalservice14/commonmark,kkiernan/commonmark,garethellis36/commonmark,garethellis36/commonmark,postalservice14/commonmark,hason/commonmark,colinodell/commonmark