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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 remove_citation_metadata(graph):
 """Remove the metadata associated with a citation. Best practice is to add this information programmatically. """

    for u, v, k in graph.edges(keys=True):
        if CITATION not in graph[u][v][k]:
            continue
        for key in list(graph[u][v][k][CITATION]):
            if key not in _CITATION_KEEP_KEYS:
                del graph[u][v][k][CITATION][key]