childKey method
Derive a new Substrate context from the current context using the provided path element.
If this context is not in public-only mode, it uses private child key derivation. Otherwise, it uses public child key derivation.
Returns the new Substrate context after deriving the child key.
Implementation
Substrate childKey(SubstratePathElem pathElem) {
return !isPublicOnly ? _ckdPriv(pathElem) : _ckdPub(pathElem);
}