Skylark Documentation: sort methods by method signature

getMethods ordering is not guaranteed and actually change
depending on minor difference in the class path.

PiperOrigin-RevId: 171093246

src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
index de65ace..133cc00 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
@@ -21,6 +21,7 @@
 import com.google.common.cache.LoadingCache;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSortedMap;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.devtools.build.lib.events.Location;
@@ -39,6 +40,7 @@
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
@@ -138,7 +140,8 @@
    */
   public static ImmutableMap<Method, SkylarkCallable> collectSkylarkMethodsWithAnnotation(
       Class<?> classObj) {
-    ImmutableMap.Builder<Method, SkylarkCallable> methodMap = ImmutableMap.builder();
+    ImmutableSortedMap.Builder<Method, SkylarkCallable> methodMap
+        = ImmutableSortedMap.orderedBy(Comparator.comparing(Object::toString));
     for (Method method : classObj.getMethods()) {
       // Synthetic methods lead to false multiple matches
       if (!method.isSynthetic()) {