`java.util.List<E>`

    @Contract(pure = true)
    public abstract boolean contains(
        Object o
    )

Returns `true` if this list contains the specified element. More formally, returns `true` if and only if this list contains at least one element `e` such that `(o==null ? e==null : o.equals(e))`.

Overrides: | `contains` in interface `Collection`
Params: | `o` – element whose presence in this list is to be tested
Returns: | `true` if this list contains the specified element
Throws: | `ClassCastException` – if the type of the specified element is incompatible with this list (optional) `NullPointerException` – if the specified element is null and this list does not permit null elements (optional)

< java 1.7 >