def get_feature_depth(feature, stop_at=None):
    """Helper method to allow caching of feature.get_depth()
    Why here and not in FeatureBase?  This keeps the caching
    local to DFS.
    """
    hash_key = hash(f"{feature.get_name()}{feature.dataframe_name}{stop_at}")
    if cached_depth := feature_cache.get(CacheType.DEPTH, hash_key):
        return cached_depth
    depth = feature.get_depth(stop_at=stop_at)
    feature_cache.add(CacheType.DEPTH, hash_key, depth)
    return depth
Helper method to allow caching of feature.get_depth()
    Why here and not in FeatureBase?  This keeps the caching
    local to DFS.
    
featuretools/synthesis/deep_feature_synthesis.py