and removemin operations the other methods are query operation min and the generic collection operations size and isempty note that we allow priority queue to have multiple entries with the same key java priority queue interface java interfacecalled priorityqueuefor the priority queue adt is shown in code fragment code fragment queue adt java interface for the priority it should now be obvious that the priority queue adt is much simpler than the sequence adt this simplicity is due to the fact that elements in priority queue are inserted and removed based entirely on their keyswhereas elements are inserted and removed in sequence based on their positions and indices example the following table shows series of operations and their effects on an initially empty priority queue we denote with an entry object returned by method insert the "priority queuecolumn is somewhat deceiving since it shows the entries sorted by key this is more than is required of apriority queue operation output priority queue