Returns a value as sequence.

// from array
var seq1 = Enumerable.asEnumerable([1, 2, 3]);

// from ObservableArray
var seq2 = Enumerable.asEnumerable(new ObservableArray([11, 22, 33]));

// from string
var seq3 = Enumerable.asEnumerable('Marcel Kloubert');

// from object
var seq4 = Enumerable.asEnumerable({
    A: 1,
    B: 2
});

// THROWS EXCEPTION
Enumerable.asEnumerable(666);

// (false)
var nonSeq = Enumerable.asEnumerable(667, false);