 => {
        const { ctx, width, height } = chart;
        ctx.save();
        ctx.globalCompositeOperation = 'destination-over';
        ctx.fillStyle = opts.color || '#fff';
        ctx.fillRect(0,0,width,height);
        ctx.restore();
      }
    };

    function buildChartConfig() {
      const labels = [];
      const labelIdx = state.labelColumn;
      
      const startRow = state.hasHeader ? 1 : 0;
      for (let r=startRow; r<state.rows.length; r++) labels.push(String(state.rows[r][labelIdx] ?? '