int' object is not iterable while implementing min max into queue

Question

I am trying to implement min and max into a queue:

class Queue:
"""Queue implementation as a list"""

def __init__(self):
    """Create new queue"""
    self._items = []

def is_empty(self):
    """Check if the queue is empty"""
    return not bool(self._items)

def enqueue(self, item):
    """Add an item to the queue"""
    self._items.insert(0, item)

def dequeue(self):
    """Remove an item from the queue"""
    return self._items.pop()

def size(self):
    """Get the number of items in the queue"""
    return len(self._items)

def find_min(self):
    return sorted(self._items[0])  <=min

def find_max(self):
    return sorted(self._items[-1])  <=max

When I try to call find_max I seem to be run into this error:

TypeError: 'int' object is not iterable

Im not entirely sure how to fix this, or if the code is just wack.