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 >