# Sandbox.HasImplementationAttribute

In ActionGraph, this type parameter can only be satisfied by a type `TArg`, such
that there exists at least one non-abstract type that extends / implements both
`TArg` and [Sandbox.HasImplementationAttribute.BaseType](/api/Sandbox.HasImplementationAttribute/BaseType).

- Kind: attribute
- Namespace: `Sandbox`
- Assembly: `Sandbox.System`
- Modifiers: sealed

## Constructors

- [`HasImplementationAttribute`](/api/Sandbox.HasImplementationAttribute/.ctor)

## Properties

- [`BaseType`](/api/Sandbox.HasImplementationAttribute/BaseType): Base class or interface for which there must exist an extending / implementing type.