Binder should automatically create intermediate objects if they are null

public class Order {
	@OneToOne
	private Customer customer;
}
public class Customer {
	@NotNull
	@NotEmpty
	private String firstName;
}

protected TextField firstName = new TextField();

BeanValidationBinder<Order> binder = new BeanValidationBinder<>(Order.class);
binder.bind(firstName, "customer.firstName");
binder.setBean(new Order());

causes

java.lang.NullPointerException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.vaadin.data.BeanPropertySet.invokeWrapExceptions(BeanPropertySet.java:357)
	at com.vaadin.data.BeanPropertySet.access$1(BeanPropertySet.java:354)
	at com.vaadin.data.BeanPropertySet$NestedBeanPropertyDefinition.lambda$0(BeanPropertySet.java:219)
	at com.vaadin.data.Binder$BindingImpl.convertDataToFieldType(Binder.java:899)
	at com.vaadin.data.Binder$BindingImpl.initFieldValue(Binder.java:890)
	at com.vaadin.data.Binder$BindingImpl.access$0(Binder.java:885)
	at com.vaadin.data.Binder.lambda$1(Binder.java:1341)
	at java.lang.Iterable.forEach(Iterable.java:75)
	at com.vaadin.data.Binder.setBean(Binder.java:1341)
	

because the Customer bean is not created before trying to run its getter.

Start by reading the nested-property handling in com.vaadin.data.BeanPropertySet, especially NestedBeanPropertyDefinition, and the binding initialization path in com.vaadin.data.Binder. Reproduce the NullPointerException with the Order, Customer, BeanValidationBinder, and firstName example; done means binding customer.firstName on a new Order no longer fails because the intermediate Customer is null.