def get_layer_uid(layer_name=''):
    'Helper function, assigns unique layer IDs.'
    if (layer_name not in _LAYER_UIDS):
        _LAYER_UIDS[layer_name] = 1
        return 1
    else:
        _LAYER_UIDS[layer_name] += 1
        return _LAYER_UIDS[layer_name]
Helper function, assigns unique layer IDs.
def get_layer_uid(layer_name=):
    
    if (layer_name not in _LAYER_UIDS):
        _LAYER_UIDS[layer_name] = 1
        return 1
    else:
        _LAYER_UIDS[layer_name] += 1
        return _LAYER_UIDS[layer_name]