code: public Entry<T> enqueue(T value, double priority) {
          checkPriority(priority);
  
          /* Create the entry object, which is a circularly-linked list of length
           * one.
           */
          Entry<T> result = new Entry<T>(value, priority);
  
          /* Merge this singleton list with the tree list. */
          mMin = mergeLists(mMin, result);
  
          /* Increase the size of the heap; we just added something. */
          ++mSize;
  
          /* Return the reference to the new element. */
          return result;
      }
docs: Inserts the specified element into the Fibonacci heap with the specified
  priority.  Its priority must be a valid double, so you cannot set the
  priority to NaN.
  
  @param value    The value to insert.
  @param priority Its priority, which must be valid.
  @return An Entry representing that element in the tree.