change the from plotting with a line to plotting with a marker

[Dmitry Hits]

How do I change the from plotting with a line to plotting with a marker for ParabolicSAR indicator. I've tried:

class ParabolicSAR(ta_ind.SAR):
    plotlines = {'SAR': dict(
        marker='o', color='blue',
        markersize=8.0, fillstyle='full')}

then in Strategy:

def __init__(self):
      self.Parabolic_SAR = ParabolicSAR(self.datas[0].high, self.datas[0].low, plotlinelabels=True)

It did not do it

Am I on a right track?

Advice appreciated!

[backtrader]

ls='' to disable linestyle.

It's already so in the built-in PSAR ...