https://docs.oracle.com/javase/jp/15/docs/api/java.base/java/net/DatagramSocketImpl.html
DatagramSocketImpl (Java SE 15 & JDK 15)
declaration: module: java.base, package: java.net, class: DatagramSocketImpl
java sejdk
https://developer.android.com/reference/kotlin/java/net/DatagramSocketImpl
DatagramSocketImpl | API reference | Android Developers
api referenceandroiddevelopers