Javadocs.

src/main/java/net/rubygrapefruit/platform/FileSystems.java

@@ -10,6 +10,7 @@ public interface FileSystems extends NativeIntegration {
     /**
      * Returns the set of all file systems for the current machine.
      *
+     * @return The set of file systems. Never returns null.
      * @throws NativeException On failure.
      */
     @ThreadSafe

src/main/java/net/rubygrapefruit/platform/Native.java

@@ -56,7 +56,7 @@ public class Native {
     /**
      * Locates a native integration of the given type.
      *
-     * @return The native integration.
+     * @return The native integration. Never returns null.
      * @throws NativeIntegrationUnavailableException When the given native integration is not available on the current
      * machine.
      * @throws NativeException On failure to load the native integration.

src/main/java/net/rubygrapefruit/platform/Terminal.java

@@ -37,6 +37,7 @@ public interface Terminal {
     /**
      * Returns the size of the terminal. Supported by all terminals.
      *
+     * @return The current terminal size. Never returns null.
      * @throws NativeException On failure.
      */
     @ThreadSafe

src/main/java/net/rubygrapefruit/platform/Terminals.java

@@ -25,6 +25,7 @@ public interface Terminals extends NativeIntegration {
     /**
      * Returns the terminal attached to the given output.
      *
+     * @return The terminal. Never returns null.
      * @throws NativeException When the output is not attached to a terminal.
      */
     @ThreadSafe

src/main/java/net/rubygrapefruit/platform/ThreadSafe.java

@@ -1,7 +1,11 @@
 package net.rubygrapefruit.platform;
 
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+
 /**
  * Indicates that the given class or method is thread safe.
  */
+@Target({ElementType.TYPE, ElementType.METHOD})
 public @interface ThreadSafe {
 }