Removes the first occurrence of the specified element from this deque. If the deque does not contain the element, it is unchanged. More formally, removes the first element e such that (o==null ? e==null : o.equals(e)) (if such an element exists). Returns true if this deque contained the specified element (or equivalently, if this deque changed as a result of the call).

Parameters:

o

element to be removed from this deque, if present

Returns:  true if an element was removed as a result of this call

Exceptions:

ClassCastException		if the class of the specified element is incompatible with this deque (optional)
NullPointerException		if the specified element is null and this deque does not permit null elements (optional)