Begin implementation of CheckStyle style checking

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

paper-api/src/main/java/org/bukkit/conversations/ExactMatchConversationCanceller.java

@@ -18,7 +18,7 @@ public class ExactMatchConversationCanceller implements ConversationCanceller {
     public ExactMatchConversationCanceller(@NotNull String escapeSequence) {
         this.escapeSequence = escapeSequence;
     }
-    
+
     public void setConversation(@NotNull Conversation conversation) {}
 
     public boolean cancelBasedOnInput(@NotNull ConversationContext context, @NotNull String input) {

paper-api/src/main/java/org/bukkit/conversations/FixedSetPrompt.java

@@ -12,7 +12,7 @@ import java.util.List;
  * response from the user.
  */
 public abstract class FixedSetPrompt extends ValidatingPrompt {
-    
+
     protected List<String> fixedSet;
 
     /**

paper-api/src/main/java/org/bukkit/conversations/PluginNameConversationPrefix.java

@@ -9,17 +9,17 @@ import org.jetbrains.annotations.NotNull;
  * that displays the plugin name in front of conversation output.
  */
 public class PluginNameConversationPrefix implements ConversationPrefix {
-    
+
     protected String separator;
     protected ChatColor prefixColor;
     protected Plugin plugin;
-    
+
     private String cachedPrefix;
-    
+
     public PluginNameConversationPrefix(@NotNull Plugin plugin) {
         this(plugin, " > ", ChatColor.LIGHT_PURPLE);
     }
-    
+
     public PluginNameConversationPrefix(@NotNull Plugin plugin, @NotNull String separator, @NotNull ChatColor prefixColor) {
         this.separator = separator;
         this.prefixColor = prefixColor;