code: def antialias(self, a):
      self._antialias = a
      self.fshader["antialias"] = float(a)
  
imports: from .base_filter import Filter
  from ..shaders import Function, Varying
  from ...color import colormap, Color
label_desc: Use image node_id 9 for calling the IsolineFilter obj's underlying member method code with example usage: obj.antialias(a) without return types