Problem is I don't understand how to create a tree. I have gone through many code examples on trees but I don't even know how to work with/handle a node and hence I don't understand how the node class works(that was present in all the program examples ). When i try to use methods such as appendChild(as mentioned in java docs),I get an error,and I am asked to create one such appendChild method inside that node class within the main program. Couldn't understand why that happened.
I am given integer pairs((u,v) meaning there is an edge between u & v) of nodes and I also need to know if any Element-to-node conversion is required for using u and v(of type integer) as nodes.
Please bear with me since my basics are weak. Little explanation on how the entire thing works/functions would be very helpful.Thank you.

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