Return the hash of the file’s children.
Return a hash of the file’s children, which is a fingerprint of it. When two files have the same childrenHash, it is guaranteed that they have the same children. This has a significance when comparing different versions of the same websites.
Note that the format of the childrenHash is not fixed. The only guarantee is that it is a HEX string no longer than 256 bytes (in HEX form).
An example childrenHash.