code: def iter_xCharts(self):
          
          plot_tags = (
              qn('c:area3DChart'), qn('c:areaChart'), qn('c:bar3DChart'),
              qn('c:barChart'), qn('c:bubbleChart'), qn('c:doughnutChart'),
              qn('c:line3DChart'), qn('c:lineChart'), qn('c:ofPieChart'),
              qn('c:pie3DChart'), qn('c:pieChart'), qn('c:radarChart'),
              qn('c:scatterChart'), qn('c:stockChart'), qn('c:surface3DChart'),
              qn('c:surfaceChart')
          )
  
          for child in self.iterchildren():
              if child.tag not in plot_tags:
                  continue
              yield child
docs: Generate each xChart child element in document.