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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def number_of_interactions(G, u=None, v=None, t=None):
 """Return the number of edges between two nodes at time t. Parameters u, v : nodes, optional (default=all edges) If u and v are specified, return the number of edges between u and v. Otherwise return the total number of all edges. t : snapshot id (default=None) If None will be returned the number of edges on the flattened graph. Returns ------- nedges : int The number of edges in the graph. If nodes u and v are specified return the number of edges between those nodes. Examples -------- """

    return G.number_of_interactions(u, v, t)