There are some redundant import statements in sun.security.ec, like the below,

# ECKeyPairGenerator
import java.io.IOException;
import java.math.BigInteger;

# SunEC
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import sun.security.ec.ed.EdDSAAlgorithmParameters;
import sun.security.util.KnownOIDs;

# XDHPublicKeyImpl
import java.security.PublicKey;