Making line example work (has some API changed?)

This code was giving:

    AttributeError: 'NoneType' object has no attribute 'line'

Using:
In [1]: import bokeh
In [2]: bokeh.__version__
Out[2]: '0.6.1'

If I actually look what figure returns (in iPython):
    figure?
    Type:       function
    String Form:<function figure at 0xacc802c>
    File:       /usr/local/lib/python2.7/dist-packages/bokeh/plotting.py
    Definition: figure(**kwargs)
    Docstring:
    Activate a new figure for plotting.
    
    All subsequent plotting operations will affect the new figure.
    
    This function accepts all plot style keyword parameters.
    
    Returns:
        None

Is this file (and probably others) outdated in some way?
I'm trying to use bokeh for the first time (on a ubuntu 12.04 without using conda, just doing pip install of bokeh and the related needed libraries).