diff --git a/src/main/java/org/kohsuke/github/GHRepository.java b/src/main/java/org/kohsuke/github/GHRepository.java
index c5ddd443e..e3fbc8cea 100644
--- a/src/main/java/org/kohsuke/github/GHRepository.java
+++ b/src/main/java/org/kohsuke/github/GHRepository.java
@@ -2967,12 +2967,15 @@ public class GHRepository extends GHObject {
     /**
      * Streams a zip archive of the repository, optionally at a given <code>ref</code>.
      *
+     * @param <T>
+     *            the type of result
      * @param streamFunction
      *            The {@link InputStreamFunction} that will process the stream
      * @param ref
      *            if <code>null</code> the repository's default branch, usually <code>master</code>,
      * @throws IOException
      *             The IO exception.
+     * @return the result of reading the stream.
      */
     public <T> T readZip(InputStreamFunction<T> streamFunction, String ref) throws IOException {
         return downloadArchive("zip", ref, streamFunction);
@@ -2981,19 +2984,23 @@ public class GHRepository extends GHObject {
     /**
      * Streams a tar archive of the repository, optionally at a given <code>ref</code>.
      *
+     * @param <T>
+     *            the type of result
      * @param streamFunction
      *            The {@link InputStreamFunction} that will process the stream
      * @param ref
      *            if <code>null</code> the repository's default branch, usually <code>master</code>,
      * @throws IOException
      *             The IO exception.
+     * @return the result of reading the stream.
      */
     public <T> T readTar(InputStreamFunction<T> streamFunction, String ref) throws IOException {
         return downloadArchive("tar", ref, streamFunction);
     }
 
-    private <T> T downloadArchive(@Nonnull String type, @CheckForNull String ref, @Nonnull InputStreamFunction<T> streamFunction)
-            throws IOException {
+    private <T> T downloadArchive(@Nonnull String type,
+            @CheckForNull String ref,
+            @Nonnull InputStreamFunction<T> streamFunction) throws IOException {
         requireNonNull(streamFunction, "Sink must not be null");
         String tailUrl = getApiTailUrl(type + "ball");
         if (ref != null) {
diff --git a/src/main/java/org/kohsuke/github/function/FunctionThrows.java b/src/main/java/org/kohsuke/github/function/FunctionThrows.java
index bfa5d6619..cb23cc577 100644
--- a/src/main/java/org/kohsuke/github/function/FunctionThrows.java
+++ b/src/main/java/org/kohsuke/github/function/FunctionThrows.java
@@ -2,8 +2,24 @@ package org.kohsuke.github.function;
 
 /**
  * A functional interface, equivalent to {@link java.util.function.Function} but that allows throwing {@link Throwable}
+ *
+ * @param <T>
+ *            the type of input
+ * @param <R>
+ *            the type of output
+ * @param <E>
+ *            the type of error
  */
 @FunctionalInterface
 public interface FunctionThrows<T, R, E extends Throwable> {
+    /**
+     * Apply r.
+     *
+     * @param input
+     *            the input
+     * @return the r
+     * @throws E
+     *             the e
+     */
     R apply(T input) throws E;
 }
diff --git a/src/main/java/org/kohsuke/github/function/InputStreamFunction.java b/src/main/java/org/kohsuke/github/function/InputStreamFunction.java
index ff342097d..efad6fcd1 100644
--- a/src/main/java/org/kohsuke/github/function/InputStreamFunction.java
+++ b/src/main/java/org/kohsuke/github/function/InputStreamFunction.java
@@ -6,6 +6,8 @@ import java.io.InputStream;
 /**
  * A functional interface, equivalent to {@link java.util.function.Function} but that allows throwing {@link Throwable}
  *
+ * @param <R>
+ *            the type to of object to be returned
  */
 @FunctionalInterface
 public interface InputStreamFunction<R> extends FunctionThrows<InputStream, R, IOException> {