code: public void modelNormalInstruction(Instruction ins, int numWordsConsumed, int numWordsProduced) {
          modelInstruction(ins, numWordsConsumed, numWordsProduced, getDefaultValue());
      }
docs: Model the stack for instructions handled by handleNormalInstruction().
  Subclasses may override to provide analysis-specific behavior.
  
  @param ins
  the Instruction to model
  @param numWordsConsumed
  number of stack words consumed
  @param numWordsProduced
  number of stack words produced