'Initialize PlotlyRenderer obj.
PlotlyRenderer obj is called on by an Exporter object to draw
matplotlib objects like figures, axes, text, etc.
All class attributes are listed here in the __init__ method.'

def __init__(self):

    self.plotly_fig = go.Figure()
    self.mpl_fig = None
    self.current_mpl_ax = None
    self.bar_containers = None
    self.current_bars = []
    self.axis_ct = 0
    self.x_is_mpl_date = False
    self.mpl_x_bounds = (0, 1)
    self.mpl_y_bounds = (0, 1)
    self.msg = 'Initialized    PlotlyRenderer\n'
