Don't cast a nullable value to a non nullable typeDRT-W1079

DON'T cast a nullable value to a non nullable type. This hides a null check and most of the time it is not what is expected.

BAD:

class A {}
class B extends A {}

A? a;
var v = a as B;
var v = a as A;

GOOD:

class A {}
class B extends A {}

A? a;
var v = a! as B;
var v = a!;