q = PriorityQueue()
assert (q is not None)
assert (hasattr(q, "items"))
assert (hasattr(q, "insert"))
assert (hasattr(q, "delete"))
assert (hasattr(q, "is_empty"))
# A,1 B,2 C,3 D,4 E,5, F,6, G,7
q.insert("C", 3)
assert (len(q.items) == 1)
assert (q.items[0].priority == 3)
assert (q.items[0].content == "C")
assert (str(q) == "(C,3)")
item = q.delete()
assert (item.priority == 3)
assert (item.content == "C")
assert (len(q.items) == 0)
assert (str(q) == "<<E>>")
q.insert("C", 3)
assert (len(q.items) == 1)
assert (q.items[0].priority == 3)
assert (q.items[0].content == "C")
q.insert("B", 2)
assert (len(q.items) == 2)
assert (q.items[0].priority == 2)
assert (q.items[0].content == "B")
assert (q.items[1].priority == 3)
