TEST-ONLY: hydrate serialized and render it onto an already-parsed svg
node (as returned by __parseSvgForTest), reusing that SAME node — see
__parseSvgForTest for why this matters. Returns the in-document-order
active-layer fingerprint, same shape as __renderActiveLayers. Not part
of the public API.
TEST-ONLY: hydrate
serializedand render it onto an already-parsedsvgnode (as returned by__parseSvgForTest), reusing that SAME node — see__parseSvgForTestfor why this matters. Returns the in-document-order active-layer fingerprint, same shape as__renderActiveLayers. Not part of the public API.