code: public static int getIdOrAllocateFor(String slashedClassName) {
  		int id = getIdFor(slashedClassName);
  		if (id == -1) {
  			id = allocateId(slashedClassName);
  		}
  		return id;
  	}
docs: Return the id for a particular type. This method will not allocate a new id if the type is unknown, it will
  return -1 instead.
  
  @param slashedClassName a type name like java/lang/String
  @return the allocated ID for that type or -1 if unknown