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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 _promote_support(sup_list, uuid_dict, on_missing='handle'):
 """Promote the list of support-related uuids to Statements, if possible."""

    valid_handling_choices = ['handle', 'error', 'ignore']
    if on_missing not in valid_handling_choices:
        raise InputError('Invalid option for `on_missing_support`: \'%s\'\n'
                         'Choices are: %s.'
                         % (on_missing, str(valid_handling_choices)))
    for idx, uuid in enumerate(sup_list):
        if uuid in uuid_dict.keys():
            sup_list[idx] = uuid_dict[uuid]
        elif on_missing == 'handle':
            sup_list[idx] = Unresolved(uuid)
        elif on_missing == 'ignore':
            sup_list.remove(uuid)
        elif on_missing == 'error':
            raise UnresolvedUuidError("Uuid %s not found in stmt jsons."
                                      % uuid)
    return