docs: def height(self, height=None):
          """Returns or sets (if a value is provided) the chart's height.
  
          :param height: If given, the chart's height will be set to this."""
  
          if height is None:
              return self._height
          else:
              if not is_numeric(height):
                  raise TypeError("height must be numeric, not '%s'" % str(height))
              self._height = height