```
class TreeNode:
    def __init__(self,key,val,left=None,right=None,
                                       parent=None):
        self.key = key
        self.payload = val
        self.leftChild = left
        self.rightChild = right
        self.parent = parent

    # Instance method
    def isLeftChild(self):
        return self.parent and self.parent.leftChild == self

```

What does the last line of this code snippet mean?

[Check this for complete code](https://runestone.academy/runestone/books/published/pythonds/Trees/SearchTreeImplementation.html)