int ebnf = 0;
if ( ebnfRoot!=null ) ebnf = ebnfRoot.getType();
Choice c = null;
switch ( ebnf ) {
case ANTLRParser.OPTIONAL :
if ( alts.size()==1 ) c = new LL1OptionalBlockSingleAlt(this, ebnfRoot, alts);
else c = new LL1OptionalBlock(this, ebnfRoot, alts);
break;
case ANTLRParser.CLOSURE :
if ( alts.size()==1 ) c = new LL1StarBlockSingleAlt(this, ebnfRoot, alts);
else c = getComplexEBNFBlock(ebnfRoot, alts);