code: def toggle_y_axis(self, signal_name=None):
      if signal_name and signal_name in self.signals.keys():
          self.signals[signal_name].toggle_axis()
      else:
          for signal in self.signals.values():
              if signal.selected:
                  signal.toggle_axis()
  
file_path: coach/rl_coach/dashboard_components/signals_file_base.py
imports: import numpy
  from bokeh.models import ColumnDataSource
  from rl_coach.dashboard_components.signals import Signal
  from rl_coach.dashboard_components.globals import x_axis, x_axis_options, show_spinner
label_desc: Use image node_id 4 for calling the SignalsFileBase obj's underlying member method code with example usage: obj.toggle_y_axis(signal_name) without return types