public Object writeTransform(Field f, Class<?> clazz, Object originalValue) {
    return originalValue;
  }
Controls what field value is written during auto serialization. Override this method to
customize the data that will be written during auto serialization. This method will only be
called if {@link #transformFieldValue} returned true.

@param f the field in question
@param clazz the original class being serialized that owns this field. Note that this field may
       have been inherited from a super class by this class. If you want to find the class that
       declared this field use {@link Field#getDeclaringClass()}.
@param originalValue the value of the field that was read from the domain object.
@return the actual value to write for this field. Return <code>originalValue</code> if you
        decide not to transform the value.
@since GemFire 6.6.2
geode-core/src/main/java/org/apache/geode/pdx/ReflectionBasedAutoSerializer.java