contains
Returns true if this queue contains the specified element. More formally, returns true if and only if this queue contains at least one element e such that o.equals(e).
Return
true if this queue contains the specified element
Parameters
o
object to be checked for containment in this queue
Throws
if the class of the specified element is incompatible with this queue ({@docRoot}/java.base/java/util/Collection.html#optional-restrictions)
if the specified element is null ({@docRoot}/java.base/java/util/Collection.html#optional-restrictions)