Add Override annotations where appropriate

By: md_5 <git@md-5.net>

paper-api/src/main/java/org/bukkit/material/Gate.java

@@ -32,6 +32,7 @@ public class Gate extends MaterialData implements Directional, Openable {
         super(Material.LEGACY_FENCE_GATE, data);
     }
 
+    @Override
     public void setFacingDirection(BlockFace face) {
         byte data = (byte) (getData() & ~DIR_BIT);
 
@@ -54,6 +55,7 @@ public class Gate extends MaterialData implements Directional, Openable {
         setData(data);
     }
 
+    @Override
     public BlockFace getFacing() {
         switch (getData() & DIR_BIT) {
             case GATE_SOUTH:
@@ -69,10 +71,12 @@ public class Gate extends MaterialData implements Directional, Openable {
         return BlockFace.EAST;
     }
 
+    @Override
     public boolean isOpen() {
         return (getData() & OPEN_BIT) > 0;
     }
 
+    @Override
     public void setOpen(boolean isOpen) {
         byte data = getData();