Javadoc
If the provider determines that the entity has been provided by itself
and that the state of the specified attribute has been loaded, this
method returns LoadState.LOADED. If the provider determines that the
entity has been provided by itself and that either entity attributes with
FetchType EAGER have not been loaded or that the state of the specified
attribute has not been loaded, this methods returns LoadState.NOT_LOADED.
If a provider cannot determine the load state, this method returns
LoadState.UNKNOWN. The provider's implementation of this method must not
obtain a reference to an attribute value, as this could trigger the
loading of entity state if the entity has been provided by a different
provider.