code: def data_class_detection(self, data):
          
          assert(isinstance(data, list) or isinstance(data, tuple))
          if not isinstance(self, (LineChart, BarChart, ScatterChart)):
              # From the link above:
              #   Simple encoding is suitable for all other types of chart
              #   regardless of size.
              return SimpleData
          elif self.height < 100:
              # The link above indicates that line and bar charts less
              # than 300px in size can be suitably represented with the
              # simple encoding. I've found that this isn't sufficient,
              # e.g. examples/line-xy-circle.png. Let's try 100px.
              return SimpleData
          else:
              return ExtendedData
docs: Determines the appropriate data encoding type to give satisfactory
          resolution (http://code.google.com/apis/chart/#chart_data).