input: 
  def dropLeafNodes(head): 
      """ Drop all the leaf nodes in the given Huffman tree.
      >>> class Node:
      ...     def __init__(self, value, left=None, right=None):
      ...         self.value = value
      ...         self.left = left
      ...         self.right = right
      >>> root = Node(1, Node(2, Node(4), Node(5)), Node(3, Node(6), Node(7)))
      >>> modified_root = dropLeafNodes(root)
      >>> print_tree(modified_root)
      <<Binary Tree Print>>
      (1)
        /      \
      (2)      (3)
      # No more leaves present
      """
      
      # If node is not None and doesn't have any children 
      if head and not head.left and not head.right: 
          return None
    
      # Don't change anything if head is None 
      if not head: 
          return None
    
      # Recursively call dropLeafNodes on left and right subtrees
      head.left = dropLeafNodes(head.left) 
      head.right = dropLeafNodes(head.right) 
    
      # Return head of the modified tree
      return head
  
output:     # If node is not None and doesn't have any children 
      if head and not head.left and not head.right: 
          return None
    
      # Don't change anything if head is None 
      if not head: 
          return None
    
      # Recursively call dropLeafNodes on left and right subtrees
      head.left = dropLeafNodes(head.left) 
      head.right = dropLeafNodes(head.right) 
    
      # Return head of the modified tree
      return head