Is that a bug?

Code:
      Ext.create('Ext.chart.Chart', {
          renderTo: Ext.getBody(),
          width: 500,
          height: 300,
          animate: true,
          store: store,
          axes: [{
              type: 'Numeric',
              position: 'bottom',
              fields: ['data1'],
              label: {
                  renderer: Ext.util.Format.numberRenderer('0,0')
              },
              title: 'Sample Values',
              grid: true,
              minimum: 0
          }, {
              type: 'Category',
              position: 'left',
              fields: ['name'],
              title: 'Sample Metrics'
          }],
              axes: [{
                  type: 'Numeric',
                  position: 'left',
                  fields: ['data1'],
                  label: {
                      renderer: Ext.util.Format.numberRenderer('0,0')
                  },
                  title: 'Sample Values',
                  grid: true,
                  minimum: 0
              }, {
                  type: 'Category',
                  position: 'bottom',
                  fields: ['name'],
                  title: 'Sample Metrics'
              }],
              series: [{
                  type: 'column',
                  axis: 'left',
                  highlight: true,
                  tips: {
                    trackMouse: true,
                    width: 140,
                    height: 28,
                    renderer: function(storeItem, item) {
                      this.setTitle(storeItem.get('name') + ': ' + storeItem.get('data1') + ' $');
                    }
                  },
                  label: {
                    display: 'insideEnd',
                    'text-anchor': 'middle',
                      field: 'data1',
                      renderer: Ext.util.Format.numberRenderer('0'),
                      orientation: 'vertical',
                      color: '#333'
                  },
                  xField: 'name',
                  yField: 'data1'
              }]
      });