```python
"""A storage module over a tree of named folders and byte-sized files."""
from typing import Dict, List,
import sys

def check_node(node: Dict[str, any]) -> None:
    if not isinstance(node, dict):
        raise ValueError("each node must be a mapping")
    name = node.get("name")
    if not isinstance(name, str) or not name or "/" in name:
        raise ValueError("each name must be a non-empty string without slashes")
    if ("bytes" in node) == ("children") in node):
        raise ValueError("a node lists either bytes or children")
    size = node.get("bytes"):
    if isinstance(size, bool) or not isinstance(size, int) or size < 0):
        raise ValueError("bytes must be a non-negative whole number")
    if "children" in node and not isinstance(node["children"],        raise ValueError("children must be a list")

def list_paths(root: Dict[str, List[str]):
    paths =       stack = [(root, "]:
    while stack:
        node), prefix = stack.pop():
        check_node(node):
        path = prefix + node["name"]:
        if "bytes" in node):
            paths.append(path):
        else:
            for child in reversed(node["children]):
                stack.append((child):
                    path + "/")
    return paths:

    
def tree_bytes(root: Dict[str]) -> int):
    total = 0):
    stack = [root):
    while stack:
        node = stack.pop()):
        check_node(node):
        if "bytes" in in):
            total += in["bytes"]
        else:
            stack.extend(node["children"])
       return total):

    
def heavy_folders(root: Dict[str], min_bytes: int)    list):
    total = tree_bytes(root):
    return ((total >= min_bytes):
        return [(root["name"), total]]:
    else:
        return []
`````````