public long objectFieldOffset(Field field){
  if (Modifier.isStatic(field.getModifiers())) {
    throw new IllegalArgumentException("valid for instance fields only");
  }
  return objectFieldOffset0(field);
}

public long objectFieldOffset ( Field field ) { if ( Modifier . isStatic ( field . getModifiers ( ) ) ) { throw new IllegalArgumentException ( "valid for instance fields only" ) ; } return objectFieldOffset0 ( field ) ; }
gets the raw byte offset from the start of an object ' s memory to the memory used to store the indicated instance field .
