If the prefix matches the suffix, create a child node with only one outgoing edge, otherwise split it
If the prefix matches the suffix, create a child node with only one outgoing edge, otherwise split it

gojp/nihongo,gojp/nihongo,shawnps/nihongo,gojp/nihongo,gojp/nihongo,shawnps/nihongo,shawnps/nihongo,shawnps/nihongo