public final int getAbsoluteOffset() {
    if (offset < 0) {
      throw new RuntimeException("offset not yet known");
    }

    return addedTo.getAbsoluteOffset(offset);
  }
Gets the absolute item offset. The offset is from the start of the file which the instance was
written to.

@return {@code >= 0;} the offset
@throws RuntimeException thrown if the offset is not yet known
android/android_framework/dex-maker/src/main/java/com/android/dx/dex/file/OffsettedItem.java