Prompt $-$ Implement a linked graph, which will store nodes and edges between nodes.

After reading instructions, complete required steps. The linked graph should support the following operations:

add$\_$node$($value$)$: Adds a new node to the linked graph, with the given value.

add$\_$edge$($node$1,$ node$2)$: Adds an edge between the two given nodes in the linked graph.

bfs$($start$\_$node, target$\_$value$)$: Performs a breadth$-$first search starting from the start$\_$node and returns the first node with the given target$\_$value, or None if no such node is found.

dfs$($start$\_$node, target$\_$value$)$: Performs a depth$-$first search starting from the start$\_$node and returns the first node with the given target$\_$value, or None if no such node is found.

You should implement the linked graph using the class LinkedGraph. The linked graph should store its nodes using a separate class Node.

Do not use any built$-$in data structures in Python, such as dictionaries, lists, or sets.

Lastly, test your implementation by creating a graph and performing various operations on them $($ call functions$)$ to ensure that the graph is working as expected.