package us.myles.ViaVersion.api.protocol;

public class ProtocolVersion {
    /* Defined protocol constants */
    public static final int V1_7_1 = 4;
    public static final int V1_7_6 = 5;

    public static final int V1_8 = 47;

    public static final int V1_9 = 107;
    public static final int V1_9_1_PRE2 = 108;
}

package us.myles.ViaVersion.api.protocol;

public class ProtocolVersion {
    /* Defined protocol constants */
    public static int V1_7_1 = 4;
    public static int V1_7_6 = 5;

    public static int V1_8 = 47;

    public static int V1_9 = 107;
    public static int V1_9_1_PRE2 = 108;
}

--- 
+++ 
@@ -2,11 +2,11 @@
 
 public class ProtocolVersion {
     /* Defined protocol constants */
-    public static int V1_7_1 = 4;
-    public static int V1_7_6 = 5;
+    public static final int V1_7_1 = 4;
+    public static final int V1_7_6 = 5;
 
-    public static int V1_8 = 47;
+    public static final int V1_8 = 47;
 
-    public static int V1_9 = 107;
-    public static int V1_9_1_PRE2 = 108;
+    public static final int V1_9 = 107;
+    public static final int V1_9_1_PRE2 = 108;
 }
Change protocol constants to final fields
