public final int getAbsoluteOffset(int relative) {
    if (relative < 0) {
      throw new IllegalArgumentException("relative < 0");
    }

    if (fileOffset < 0) {
      throw new RuntimeException("fileOffset not yet set");
    }

    return fileOffset + relative;
  }
Returns the absolute file offset, given an offset from the start of this instance's output.
This is only valid to call once this instance has been assigned a file offset (via {@link
#setFileOffset}).

@param relative {@code >= 0;} the relative offset
@return {@code >= 0;} the corresponding absolute file offset
android/android_framework/dex-maker/src/main/java/com/android/dx/dex/file/Section.java