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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_nested( bels: list, char_locs: CharLocs, parsed: Parsed, errors: Errors ) -> Tuple[Parsed, Errors]: """ Parse nested BEL object """


    for sp in char_locs[
        "nested_parens"
    ]:  # sp = start parenthesis, ep = end parenthesis
        ep, level = char_locs["nested_parens"][sp]
        if ep == -1:
            ep = len(bels) + 1
        parsed[(sp, ep)] = {"type": "Nested", "span": (sp, ep)}

    return parsed, errors