<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def parse_sentence(obj: dict) -> BioCSentence:
 """Deserialize a dict obj to a BioCSentence object"""

    sentence = BioCSentence()
    sentence.offset = obj['offset']
    sentence.infons = obj['infons']
    sentence.text = obj['text']
    for annotation in obj['annotations']:
        sentence.add_annotation(parse_annotation(annotation))
    for relation in obj['relations']:
        sentence.add_relation(parse_relation(relation))
    return sentence