How do I setDomainGridlineStroke - Report Viewer - Time Series Chart Scripting

In the Report environment, I am currently using the following script to change my Time Series Chart
Gridline colors.

from java.awt import Color
from org.jfree.chart.plot import CategoryPlot

plot = chart.getPlot()

plot.setDomainGridlinePaint(Color.black)
plot.setRangeGridlinePaint(Color.black)

Now I would like to change the stroke and make these gridlines thicker.
The script below is where I’m at with no luck so far. My last attempt I used a value of 5.5 just to see if anything changed (it did not). I don’t even know the valid input range. I am using info found at this site.
http://www.jfree.org/jfreechart/api/javadoc/org/jfree/chart/plot/CategoryPlot.html#setDomainGridlineStroke-java.awt.Stroke-

from java.awt import Color
from org.jfree.chart.plot import CategoryPlot

plot = chart.getPlot()

plot.setDomainGridlinePaint(Color.black)
plot.setRangeGridlinePaint(Color.black)
plot.setDomainGridlineStroke(BasicStroke(5.5))
plot.setRangeGridlineStroke(BasicStroke(5.5))

Ignition Support helped solve this one.

#Import Java classes - Color & JFreeChart
from java.awt import Color
from org.jfree.chart.plot import CategoryPlot
from java.awt import BasicStroke

#Define Stroke
stroke = BasicStroke(.75)

#get Plot of Current Chart
plot = chart.getPlot()
#Set color of domain and range gridlines
plot.setDomainGridlinePaint(Color.black)
plot.setDomainGridlineStroke(stroke)
plot.setRangeGridlinePaint(Color.black)
plot.setRangeGridlineStroke(stroke)