anchor.diff:  comparatorType returns [shared_ptr<cql3_type::raw> t]
       : n=native_type     { $t = cql3_type::raw::from(n); }
       | c=collection_type { $t = c; }
  -#if 0
       | tt=tuple_type     { $t = tt; }
  +#if 0
       | id=userTypeName   { $t = CQL3Type.Raw.userType(id); }
       | K_FROZEN '<' f=comparatorType '>'
         {
  
positive.code:         { if (t) { $pt = cql3::cql3_type::raw::set(t); } }
      ;
  
  #if 0
  tuple_type returns [CQL3Type.Raw t]
      : K_TUPLE '<' { List<CQL3Type.Raw> types = new ArrayList<>(); }
           t1=comparatorType { types.add(t1); } (',' tn=comparatorType { types.add(tn); })*
        '>' { $t = CQL3Type.Raw.tuple(types); }
      ;
  
  username
      : IDENT
      | STRING_LITERAL
  
negative.code: #include "cql3/sets.hh"
  #include "cql3/lists.hh"
  #include "cql3/type_cast.hh"
  #include "cql3/tuples.hh"
  #include "cql3/functions/function_name.hh"
  #include "cql3/functions/function_call.hh"
  #include "core/sstring.hh"
  