class_docstr: Base class for maps
code: def _compute_y_labels(self):
      pass
  
file_path: pygal/pygal/graph/map.py
imports: from pygal.etree import etree
  from pygal.graph.graph import Graph
  from pygal.util import alter, cached_property, cut, decorate
label_desc: Use image node_id 7 for calling the BaseMap obj's underlying member method code with example usage: obj._compute_y_labels() without return types