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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 fill_childgoid2obj(childgoid2obj, parent_obj):
 """Fill childgoid2obj with all child key GO IDs and their objects."""

    for child_obj in parent_obj.children:
        if child_obj.id not in childgoid2obj:
            childgoid2obj[child_obj.id] = child_obj
            fill_childgoid2obj(childgoid2obj, child_obj)