augmentationTarget property
The element that is augmented by this augmentation; or null if
isAugmentation is false, or there is no corresponding element to be
augmented.
The chain of augmentations should normally end with a not augmentation
InstanceElement, but might end with null immediately or after a few
intermediate elements in case of invalid code when an augmentation is
declared without the corresponding declaration.
Implementation
@experimental
@override
ExtensionTypeElement? get augmentationTarget;