private void updateKey(int index, Field updateKey) throws IOException {

		// Adjust key data space
		int offset = moveKeys(index + 1, getKeyLength(index) - updateKey.length());

		// Update key data
		updateKey.write(buffer, offset);
		putKeyOffset(index, offset);
	}
Update the child key associated with the specified key index.
Other entries are shifted as necessary to accommodate the new key length for 
the updated entry.
@param index child key index
@param updateKey updated child node key
Ghidra/Framework/DB/src/main/java/db/VarKeyInteriorNode.java