code: func (c *linuxContainer) addUidGidMappings(sys *syscall.SysProcAttr) error {
  	if c.config.UidMappings != nil {
  		sys.UidMappings = make([]syscall.SysProcIDMap, len(c.config.UidMappings))
  		for i, um := range c.config.UidMappings {
  			sys.UidMappings[i].ContainerID = um.ContainerID
  			sys.UidMappings[i].HostID = um.HostID
  			sys.UidMappings[i].Size = um.Size
  		}
  	}
  	if c.config.GidMappings != nil {
  		sys.GidMappings = make([]syscall.SysProcIDMap, len(c.config.GidMappings))
  		for i, gm := range c.config.GidMappings {
  			sys.GidMappings[i].ContainerID = gm.ContainerID
  			sys.GidMappings[i].HostID = gm.HostID
  			sys.GidMappings[i].Size = gm.Size
  		}
  	}
  	return nil
  }
docs: // Converts IDMap to SysProcIDMap array and adds it to SysProcAttr.