code: public static int getIdFor(String slashedClassName) {
  		assert Asserts.assertNotDotted(slashedClassName);
  		for (int i = 0; i < nextTypeId; i++) {
  			if (allocatedIds[i].equals(slashedClassName)) {
  				return i;
  			}
  		}
  		return -1;
  	}
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