Changing the attributes of the bars

This example is equal to the [minimal bar-graph example minimal.html] except for
the used style to draw the bars. ...

! It is not possible to use the changebar style to change itself on a list of
data as it is shown for the bar style in the [comparing bars example
compare.html].

! We are sorry that a graph key implementation for the changebar style is
currently missing. The implementation of such a graph key needs a major rework
on the whole graph key system. This rework is planned for the near future.
