code: def __init__(
      self, level=2.0, width=2.0, antialias=1.0, color="black", **kwargs
  ):
      super(IsolineFilter, self).__init__(
          fcode=self.FRAG_SHADER, **kwargs
      )
  
      self.level = level
      self.width = width
      self.color = color
      self.antialias = antialias
  
imports: from .base_filter import Filter
  from ..shaders import Function, Varying
  from ...color import colormap, Color
label_desc: Use image node_id 1 to create a new IsolineFilter object from inherited base classes: Filter with example: obj = IsolineFilter(level, width, antialias, color)