code: def createProgBuilder(env):
      
  
      try:
          program = env['BUILDERS']['Program']
      except KeyError:
          import SCons.Defaults
          program = SCons.Builder.Builder(action = SCons.Defaults.LinkAction,
                                          emitter = '$PROGEMITTER',
                                          prefix = '$PROGPREFIX',
                                          suffix = '$PROGSUFFIX',
                                          src_suffix = '$OBJSUFFIX',
                                          src_builder = 'Object',
                                          target_scanner = ProgramScanner)
          env['BUILDERS']['Program'] = program
  
      return program
docs: This is a utility function that creates the Program
      Builder in an Environment if it is not there already.
  
      If it is already there, we return the existing one.