def add_child(self, child):
        '''Add child to ``Node`` object

        Args:
            ``child`` (``Node``): The child ``Node`` to be added
        '''
        if not isinstance(child, Node):
            raise TypeError("child must be a Node")
        self.children.append(child); child.parent = self
Add child to ``Node`` object

        Args:
            ``child`` (``Node``): The child ``Node`` to be added