code: @NullSafe
    public static boolean assignableTo(Class<?> fromType, Class<?> toType) {
      return (toType != null && (fromType == null || toType.isAssignableFrom(fromType)));
    }
docs: Determines whether a given Class type is assignable to a declared Class type.  A given Class type is assignable to
  a declared Class type if it is in the same Class type hierarchy, i.e. the given Class type is a subclass,
  or sub-interface of the declared Class type.  Null is also assignable to the declared (to) Class type.
  
  @param fromType the Class type evaluated for assignment compatibility with the declared Class type.
  @param toType the declared Class type defining the type hierarchy, or bounds on the given Class type for
  assignment compatibility.
  @return a boolean value indicating given Class type is assignable to the declared Class type.
  @see java.lang.Class#isAssignableFrom(Class)
  @see #instanceOf(Object, Class)