code: def screen(obs):
      """Give a crude ascii rendering of feature_screen."""
      unit_type = obs.feature_screen.unit_type
      selected = obs.feature_screen.selected
      visibility = obs.feature_screen.visibility_map
      max_y, max_x = unit_type.shape
      out = _summary(obs, "screen", max_y * 2) + "\n"
      for y in range(max_y):
          started = False
          for x in range(max_x):
              s = selected[y, x]
              u = unit_type[y, x]
              v = visibility[y, x]
              if started and not s:
                  out += ")"
              elif not started and s:
                  out += "("
              else:
                  out += " "
              if u:
                  out += _printable_unit_types.get(u, str(u))
              else:
                  out += VISIBILITY[v]
              started = s
          if started:
              out += ")"
          out += "\n"
      return out
  
imports: from pysc2.lib import units
label_desc: Use image node_id 3 for calling a global function with example usage: screen(obs) and returns: out