Exception that indicates a passed argument was null.
Prior to ScalaTest and Scalactic 3.0.0, a null argument (where non-null was required)
would result in a NullPointerException. Although throwing NullPointerException is the
tradition in Java APIs, Scala.js does not support a NullPointerException. To make the behavior
the same on both the JVM and Scala.js, the change to throwing NullArgumentException was made throughout
the ScalaTest and Scalactic, including the requireNonNull method of trait Requirements.
Exception that indicates a validation failed.
This exception is used to indicate and describe a failed validation by the validating methods
of TrySugar and FutureSugar.
a string describing the validation failure