Contains a string representation of a property value.
	The property may be a string, or may be converted to the required
	type using the JavaBeans PropertyEditor machinery. This makes it
	possible for application developers to write custom PropertyEditor
	implementations that can convert strings to arbitrary target objects.

	Note that this is recommended for simple objects only. Configure
	more complex objects by populating JavaBean properties with
	references to other beans.

The exact type that the value should be converted to. Only needed
if the type of the target property or constructor argument is
too generic: for example, in case of a collection element.