_</tt>” whose assignment operator can accept a
<tt class="docutils literal">my_color_map</tt> argument.  In this step we'll create one such
<strong>keyword object</strong> for each parameter.  Each keyword object will be
identified by a unique <strong>keyword tag type</strong>.</p>
<!-- Revisit this

We're going to define our interface in namespace ``graphs``.  Since
users need access to the keyword objects, but not the tag types,
we'll define the keyword objects so they're accessible through
``graphs``, 