Cleaning up unused code

src/main/java/net/schmizz/sshj/transport/Encoder.java

@@ -39,19 +39,6 @@ final class Encoder
         log = loggerFactory.getLogger(getClass());
     }
 
-    private SSHPacket checkHeaderSpace(SSHPacket buffer) {
-        if (buffer.rpos() < 5) {
-            log.warn("Performance cost: when sending a packet, ensure that "
-                             + "5 bytes are available in front of the buffer");
-            SSHPacket nb = new SSHPacket(buffer.available() + 5);
-            nb.rpos(5);
-            nb.wpos(5);
-            nb.putBuffer(buffer);
-            buffer = nb;
-        }
-        return buffer;
-    }
-
     private void compress(SSHPacket buffer) {
         compression.compress(buffer);
     }

src/main/java/net/schmizz/sshj/transport/kex/Curve25519SHA256.java

@@ -16,14 +16,10 @@
 package net.schmizz.sshj.transport.kex;
 
 import net.schmizz.sshj.transport.digest.SHA256;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import java.security.GeneralSecurityException;
 
 public class Curve25519SHA256 extends AbstractDHG {
-    private static final Logger logger = LoggerFactory.getLogger(Curve25519SHA256.class);
-
     /** Named factory for Curve25519SHA256 key exchange */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<KeyExchange> {