Bokeh desired_num_ticks interaction with custom x_range

bokeh_ticks.py

import numpy as np

from bokeh.plotting import figure, show, output_file

x = range(0,100)
y = x

output_file("line.html", title="line.py example")

# p = figure(title="simple line example") # Works fine
p = figure(title="simple line example", x_range=map(lambda a: str(a), x)) # Doesn't work
p.line(x,y, color="#2222aa", line_width=2)

p.xgrid[0].ticker.desired_num_ticks = 3

show(p)