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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 logical_intf_helper(interface):
 """ Logical Interface finder by name. Create if it doesn't exist. This is useful when adding logical interfaces to for inline or capture interfaces. :param interface: logical interface name :return str href: href of logical interface """

    if interface is None:
        return LogicalInterface.get_or_create(name='default_eth').href
    elif isinstance(interface, LogicalInterface):
        return interface.href
    elif interface.startswith('http'):
        return interface
    return LogicalInterface.get_or_create(name=interface).href