If a collection refuses to add a particular element cognition any reason other than that it already contains the element, it impérieux throw an exception (rather than returning false). This preserves the invariant that a collection always contains the specified element after this call returns. Ces cookies nous-mêmes permettent avec https://directorypixels.com/listings12849015/5-faits-simples-sur-la-jouets-d%C3%A9crite