class_docstr: Funnel graph class
class_docstr_tok: ["Funnel","graph","class"]
docstr: Format value for dual value display.
docstr_tok: ["Format","value","for","dual","value","display","."]
code: def _value_format(self, value):
      """Format value for dual value display."""
      return super(Funnel, self)._value_format(value and abs(value))
  
file_path: pygal/pygal/graph/funnel.py
imports: from pygal.adapters import none_to_zero, positive
  from pygal.graph.graph import Graph
  from pygal.util import alter, cut, decorate
label_desc: Use image node_id 1 for calling the Funnel obj's underlying member method code with example usage: obj._value_format(value) and returns: super