code: static ConstantUTFInfo make(ConstantPool cp, String str) {
          ConstantInfo ci = new ConstantUTFInfo(str);
          return (ConstantUTFInfo)cp.addConstant(ci);
      }
docs: Will return either a new ConstantUTFInfo object or one already in
  the constant pool. If it is a new ConstantUTFInfo, it will be inserted
  into the pool.