- * Check if a directory exists at a given storage path.
- * Backends using key/value stores will check if the path is a
- * virtual directory, meaning there are files under the given directory.
+ * Check if a directory exists at a given storage path
+ *
+ * For backends using key/value stores, a directory is said to exist whenever
+ * there exist any files with paths using the given directory path as a prefix
+ * followed by a forward slash. For example, if there is a file called
+ * "mwstore://backend/container/dir/path.svg" then directories are said to exist
+ * at "mwstore://backend/container" and "mwstore://backend/container/dir". These
+ * can be thought of as "virtual" directories.
+ *
+ * Backends that directly use a filesystem layer might enumerate empty directories.
+ * The clean() method should always be used when files are deleted or moved if this
+ * is a concern. This is a trade-off to avoid write amplication/contention on file
+ * changes or read amplification when calling this method.