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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 edge_cost(self, node_a, node_b):
 """Returns the cost of moving between the edge that connects node_a to node_b. Returns +inf if no such edge exists."""

        cost = float('inf')
        node_object_a = self.get_node(node_a)
        for edge_id in node_object_a['edges']:
            edge = self.get_edge(edge_id)
            tpl = (node_a, node_b)
            if edge['vertices'] == tpl:
                cost = edge['cost']
                break
        return cost