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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 update_field_forward_refs(field: 'Field', globalns: Any, localns: Any) -> None: """ Try to update ForwardRefs on fields based on this Field, globalns and localns. """

    if type(field.type_) == ForwardRef:
        field.type_ = field.type_._evaluate(globalns, localns or None)  # type: ignore
        field.prepare()
    if field.sub_fields:
        for sub_f in field.sub_fields:
            update_field_forward_refs(sub_f, globalns=globalns, localns=localns)