- l -
- label() : axis
 - lane() : base_metric , filter_options , lane_summary
 - lane_count() : summary_by_lane_read< T > , metric_set< T > , flowcell_data , flowcell_layout , read_summary , run_summary
 - lane_description() : filter_options
 - lane_from_id() : base_metric
 - lane_summary() : lane_summary
 - lanes() : metric_set< T >
 - lanes_per_section() : flowcell_layout
 - last_cycle() : cycle_range
 - legacy_channel_update() : run_metrics
 - length() : heatmap_data
 - linear_fit() : linear_fit
 - list_filenames() : run_metrics
 - list_interop_filenames() : list_interop_filenames
 - ListAvailablePlotMetrics() : CoreTests
 - lower() : q_score_bin , candle_stick_point