Called immediately after a component is mounted. Setting state here will trigger re-rendering.
Called immediately after updating occurs. Not called for the initial render.
The snapshot is only present if getSnapshotBeforeUpdate is present and returns non-null.
Called immediately before a component is destroyed. Perform any necessary cleanup in this method, such as
cancelled network requests, or cleaning up any DOM elements created in componentDidMount.
value of the parent Context specified in
contextType.