code: def fit_tip_labels(self):
          
          # user entered values
          #if self.style.axes.x_domain_max or self.style.axes.y_domain_min:
          #    self.axes.x.domain.max = self.style.axes.x_domain_max
          #    self.axes.y.domain.min = self.style.axes.y_domain_min            
  
          # IF USE WANTS TO CHANGE IT THEN DO IT AFTER USING AXES
          # or auto-fit (tree height)
          #else:
          if self.style.use_edge_lengths:
              addon = self.ttree.treenode.height * .85
          else:
              addon = self.ttree.treenode.get_farthest_leaf(True)[1]
  
          # modify display for orientations
          if self.style.tip_labels:
              if self.style.orient == "right":
                  self.axes.x.domain.max = addon
              elif self.style.orient == "down":
                  self.axes.y.domain.min = -1 * addon
docs: Modifies display range to ensure tip labels fit. This is a bit hackish
          still. The problem is that the 'extents' range of the rendered text
          is totally correct. So we add a little buffer here. Should add for 
          user to be able to modify this if needed. If not using edge lengths
          then need to use unit length for treeheight.