code: func NewWithPortAllocator(allocator *portallocator.PortAllocator, proxyPath string) *PortMapper {
  	return &PortMapper{
  		currentMappings: make(map[string]*mapping),
  		Allocator:       allocator,
  		proxyPath:       proxyPath,
  	}
  }
docs: // NewWithPortAllocator returns a new instance of PortMapper which will use the specified PortAllocator