public final void setWriteSize(int writeSize) {
    if (writeSize < 0) {
      throw new IllegalArgumentException("writeSize < 0");
    }

    if (this.writeSize >= 0) {
      throw new UnsupportedOperationException("writeSize already set");
    }

    this.writeSize = writeSize;
  }
Sets the write size of this item. This may only be called once per instance, and only if the
size was unknown upon instance creation.

@param writeSize {@code > 0;} the write size, in bytes
android/android_framework/dex-maker/src/main/java/com/android/dx/dex/file/OffsettedItem.java