code: def _call_linker_cb(env, callback, args, result = None):
      
  
      Verbose = False
  
      if Verbose:
          print('_call_linker_cb: args=%r' % args)
          print('_call_linker_cb: callback=%r' % callback)
  
      try:
          cbfun = env['LINKCALLBACKS'][callback]
      except (KeyError, TypeError):
          if Verbose:
              print('_call_linker_cb: env["LINKCALLBACKS"][%r] not found or can not be used' % callback)
          pass
      else:
          if Verbose:
              print('_call_linker_cb: env["LINKCALLBACKS"][%r] found' % callback)
              print('_call_linker_cb: env["LINKCALLBACKS"][%r]=%r' % (callback, cbfun))
          if(isinstance(cbfun, collections.Callable)):
              if Verbose:
                  print('_call_linker_cb: env["LINKCALLBACKS"][%r] is callable' % callback)
              result = cbfun(env, *args)
      return result
docs: Returns the result of env['LINKCALLBACKS'][callback](*args)
      if env['LINKCALLBACKS'] is a dictionary and env['LINKCALLBACKS'][callback]
      is callable. If these conditions are not met, return the value provided as
      the *result* argument. This function is mainly used for generating library
      info such as versioned suffixes, symlink maps, sonames etc. by delegating
      the core job to callbacks configured by current linker tool