code: def visit(visitor, obj, attr, metrics):
      for g in metrics:
          advance, lsb = metrics[g]
          metrics[g] = visitor.scale(advance), visitor.scale(lsb)
  
imports: from fontTools.ttLib.ttVisitor import TTVisitor
  import fontTools.ttLib
  import fontTools.ttLib.tables.otBase
  import fontTools.ttLib.tables.otTables
  from fontTools.cffLib import VarStoreData
  import fontTools.cffLib.specializer
  from fontTools.varLib import builder
  from fontTools.misc.fixedTools import otRound
  from fontTools.ttLib.tables._g_l_y_f import VarComponentFlags
label_desc: Use image node_id 2 for calling a global function with example usage: visit(visitor, obj, attr, metrics) without return types