net.getDefaultAutoSelectFamily()
获取 socket.connect(options) 的 autoSelectFamily 选项的当前默认值。初始默认值为 true，除非提供了命令行选项 --no-network-family-autoselection。
¥Gets the current default value of the autoSelectFamily option of socket.connect(options).
The initial default value is true, unless the command line option
--no-network-family-autoselection is provided.