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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_passage(obj: dict) -> BioCPassage:
 """Deserialize a dict obj to a BioCPassage object"""

    passage = BioCPassage()
    passage.offset = obj['offset']
    passage.infons = obj['infons']
    if 'text' in obj:
        passage.text = obj['text']
    for sentence in obj['sentences']:
        passage.add_sentence(parse_sentence(sentence))
    for annotation in obj['annotations']:
        passage.add_annotation(parse_annotation(annotation))
    for relation in obj['relations']:
        passage.add_relation(parse_relation(relation))
    return passage