JSDoc
A strict comparison of an object's own properties, checking for inequality.
The `notPropEqual` assertion uses the strict inverted comparison operator
(`!==`) to compare the actual and expected arguments as Objects regarding
only their properties but not their constructors.
When they aren't equal, the assertion passes; otherwise, it fails. When
it fails, both actual and expected values are displayed in the test
result, in addition to a given message.
`equal()` can be used to test equality.
`propEqual()` can be used to test strict equality of an Object properties.