Added javadoc and copyright header.

src/lombok/NonNull.java

@@ -1,3 +1,24 @@
+/*
+ * Copyright © 2009 Reinier Zwitserloot and Roel Spilker.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
 package lombok;
 
 import java.lang.annotation.ElementType;
@@ -5,8 +26,14 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+/**
+ * Lombok is smart enough to translate any annotation named <code>@NonNull</code> or <code>@NotNull</code> in any casing and
+ * with any package name to the return type of generated getters and the parameter of generated setters and constructors,
+ * as well as generate the appropriate null checks in the setter and constructor.
+ * 
+ * You can use this annotation for the purpose, though you can also use JSR305's annotation, findbugs's, pmd's, or IDEA's, or just
+ * about anyone elses. As long as it is named <code>@NonNull</code> or <code>@NotNull</code>.
+ */
 @Target({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER, ElementType.LOCAL_VARIABLE})
 @Retention(RetentionPolicy.CLASS)
-public @interface NonNull {
-
-}
+public @interface NonNull {}