Deep Copy a Graph

Implement a function to deep copy an undirected graph, where each node contains an integer value and a list of neighbors. The undirected graph is represented as an adjacency list, for example, the graph 1 -- 2 | | 3 -- 4 can be represented as {1 [2, 3], 2 [1, 4], 3 [1, 4], 4 [2, 3]}. Input/Output Specification Input: Starting node of the undirected graph (node, Node type) Output: Starting node of the deep copied graph. Example Input: {1 [2, 3], 2 [1, 4], 3 [1, 4], 4 [2, 3]} Output: A new graph identical in structure to the input but with different address. Example Input {1 [2, 3], 2 [1, 4], 3 [1, 4], 4 [2, 3]}