code: public void readyToWrite()
      {
          addSignatureIfNeed();
          this.name_index = ((SubClass)classFile).resolveNameIndex(getSimpleName());
          this.descriptor_index = ((SubClass)classFile).resolveNameIndex(Descriptor.getDesriptor(this));
          readyToWrite = true;
      }
docs: Call to this method tells that the Attribute is ready writing. This method
  must be called before constant pool is written.