What is happening here

build.gradle

@@ -1,5 +1,5 @@
 plugins {
-	id 'fabric-loom' version '0.2.0-SNAPSHOT'
+    id 'fabric-loom' version '0.2.0-SNAPSHOT'
 }
 
 sourceCompatibility = 1.8
@@ -17,31 +17,31 @@ minecraft {
 }
 
 processResources {
-	filesMatching('fabric.mod.json') {
-		expand 'version': project.version
-	}
-	inputs.property "version", project.version
+    filesMatching('fabric.mod.json') {
+        expand 'version': project.version
+    }
+    inputs.property "version", project.version
 }
 
 repositories {
-	maven { url "https://tehnut.info/maven/" }
+    maven { url "https://tehnut.info/maven/" }
 }
 
 dependencies {
-	minecraft "com.mojang:minecraft:${minecraftVersion}"
-	mappings "net.fabricmc:yarn:${yarnVersion}"
-	modCompile "net.fabricmc:fabric-loader:0.3.4.104"
-
-	// Fabric API. This is technically optional, but you probably want it anyway.
-	modCompile "net.fabricmc:fabric:${fabricVersion}"
-	
-	modCompile "info.tehnut.pluginloader:plugin-loader:${pluginLoaderVersion}"
+    minecraft "com.mojang:minecraft:${minecraftVersion}"
+    mappings "net.fabricmc:yarn:${yarnVersion}"
+    modCompile "net.fabricmc:fabric-loader:0.3.4.104"
+
+    // Fabric API. This is technically optional, but you probably want it anyway.
+    modCompile "net.fabricmc:fabric:${fabricVersion}"
+
+    modCompile "info.tehnut.pluginloader:plugin-loader:${pluginLoaderVersion}"
 }
 
 // Loom will automatically attach sourcesJar to a RemapSourcesJar task and to the "build" task
 // if it is present.
 // If you remove this task, sources will not be generated.
 task sourcesJar(type: Jar, dependsOn: classes) {
-	classifier = 'sources'
-	from sourceSets.main.allSource
+    classifier = 'sources'
+    from sourceSets.main.allSource
 }

src/main/java/me/shedaniel/rei/gui/widget/QueuedTooltip.java

@@ -1,8 +1,6 @@
 package me.shedaniel.rei.gui.widget;
 
 
-import com.sun.istack.internal.NotNull;
-
 import java.awt.*;
 import java.util.LinkedList;
 import java.util.List;
@@ -12,7 +10,7 @@ public class QueuedTooltip {
     public Point mouse;
     public List<String> text;
     
-    public QueuedTooltip(@NotNull Point mouse, @NotNull List<String> text) {
+    public QueuedTooltip(Point mouse, List<String> text) {
         this.mouse = mouse;
         this.text = new LinkedList<>(text);
     }