Returns the potentially annotated type that this type is a member of, if this type represents a nested type. For example, if this type is
@TA O<T>.I<S> , return a representation of
@TA O<T> .
Returns null if this AnnotatedType represents a top-level type, or a local or anonymous class, or a primitive type, or void.
Returns null if this AnnotatedType is an instance of AnnotatedArrayType, AnnotatedTypeVariable, or AnnotatedWildcardType.