Function unload

unload(target: null | string | NutrientViewer.Instance | HTMLElement): boolean
Unloads an existing NutrientViewer instance.

It requires an target parameter that is a CSS selector, an HTMLElement or the reference to a NutrientViewer.Instance returned by NutrientViewer.load.
Parameters
- target: null | string | NutrientViewer.Instance | HTMLElement
  A target to unload
Returns boolean
When true, an instance of Nutrient Web SDK was unmounted.
Example: Unload Nutrient Web SDK using an instance
```
let instance = null;
NutrientViewer.load({
  document: "/sales-report.pdf",
  container: ".foo",
}).then((i) => {
  instance = i
})
.then(() => {
  // Unload the given instance
  NutrientViewer.unload(instance)
}).catch((error) => {
  console.error(error.message);
})
```
Example: Unload Nutrient Web SDK using a CSS selector
```
NutrientViewer.load({
  document: "/sales-report.pdf",
  container: ".foo",
})
.then(() => {
  // Unload the given instance
  NutrientViewer.unload(".foo")
})
```
Example: Unload Nutrient Web SDK using an HTMLElement
```
NutrientViewer.load({
  document: "/sales-report.pdf",
  container: ".foo",
})
.then(() => {
  // Unload the given instance
  NutrientViewer.unload(document.querySelector(".foo"))
})

@public
```
Throws
Will throw an error when the target is invalid but will work when it does not have a mounted Nutrient Web SDK instance.