fun Iterable<SymbolSet>.sum(excludeLookAlikeSymbols: Boolean = false): String
Concatenates the symbols of all the symbol sets, removing duplicate characters.
This method respects emoji sequences and will not remove duplicate characters if these characters are essential to displaying the embedded emoji correctly.
excludeLookAlikeSymbols - whether to remove symbols that occur in SymbolSet.lookAlikeCharacters
Return
the concatenation of all symbols of all the symbol sets, excluding duplicate characters