src/main/java/com/googlecode/objectify/impl/KeyMetadata.java
private com.google.cloud.datastore.Key getParentRaw(P pojo) {
		if (parentMeta == null)
			return null;

		final Value<Object> value = parentMeta.getValue(pojo, new SaveContext(), Path.root());
		return (value == null || value.getType() == ValueType.NULL)
				? null
				: (com.google.cloud.datastore.Key)value.get();
	}
private com.google.cloud.datastore.Key getParentRaw(P pojo) {
		if (parentMeta == null)
			return null;

		final Value<Object> value = parentMeta.getValue(pojo, new SaveContext(), Path.root());
		return (value == null || value.getType() == ValueType.NULL)
				? null
				: (com.google.cloud.datastore.Key)value.get();
	}
Get the contents of the @Parent field as a datastore key.
@return null if there was no @Parent field, or the field is null.