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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 parse_collection(obj: dict) -> BioCCollection:
 """Deserialize a dict obj to a BioCCollection object"""

    collection = BioCCollection()
    collection.source = obj['source']
    collection.date = obj['date']
    collection.key = obj['key']
    collection.infons = obj['infons']
    for doc in obj['documents']:
        collection.add_document(parse_doc(doc))
    return collection