def scan_1d_mesh(cdl_scanner):
    """Return a scan representing a 1d (edges only) mesh."""
    test_cdl = """
    netcdf data_C4 {
    dimensions:
        edge_dim = 6 ;
        num_node = 8 ;
        num_ends = 2 ;

    variables:
        double sample_data(edge_dim) ;
            sample_data:long_name = "sample_data" ;
            sample_data:coordinates = "latitude longitude" ;
            sample_data:location = "edge" ;
            sample_data:mesh = "topology" ;
        double latitude(edge_dim) ;
            latitude:units = "degrees_north" ;
            latitude:standard_name = "latitude" ;
            latitude:long_name = "latitude of 2D edge centres" ;
            latitude:bounds_long_name = "latitude of 2D mesh edges." ;
        double longitude(edge_dim) ;
            longitude:units = "degrees_east" ;
            longitude:standard_name = "longitude" ;
            longitude:long_name = "longitude of 2D edge centres" ;
            longitude:bounds_long_name = "longitude of 2D mesh edges." ;
        double node_lat(num_node) ;
            node_lat:standard_name = "latitude" ;
            node_lat:long_name = "latitude of 2D mesh nodes." ;
            node_lat:units = "degrees_north" ;
        double node_lon(num_node) ;
            node_lon:standard_name = "longitude" ;
            node_lon:long_name = "longitude of 2D mesh nodes." ;
            node_lon:units = "degrees_east" ;
        int edge_nodes(edge_dim, num_ends) ;
            edge_nodes:long_name = "Map every edge to its endpoints." ;
            edge_nodes:cf_role = "edge_node_connectivity" ;
            edge_nodes:start_index = 1 ;
        int topology ;
            topology:cf_role = "mesh_topology" ;
            topology:topology_dimension = 1L ;
            topology:node_coordinates = "node_lat node_lon" ;
            topology:edge_coordinates = "latitude longitude" ;
            topology:edge_node_connectivity = "edge_nodes" ;
            topology:edge_dimension = "edge_dim" ;
            topology:long_name = "Topology data of 1D unstructured mesh" ;

    // global attributes:
            :Conventions = "UGRID-1.0" ;
    }
    """
    return cdl_scanner.scan(test_cdl)