Fix ErrorProne warnings in skylark tests.

PiperOrigin-RevId: 279111146
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
index 5884d96..7691e75 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
@@ -20,7 +20,6 @@
 import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.devtools.build.lib.analysis.config.transitions.NoTransition;
 import com.google.devtools.build.lib.analysis.skylark.SkylarkAttr;
@@ -1161,7 +1160,7 @@
         "y = struct(c = 1, d = 2)",
         "z = x + y\n");
     StructImpl z = (StructImpl) lookup("z");
-    assertThat(z.getFieldNames()).isEqualTo(ImmutableSet.of("a", "b", "c", "d"));
+    assertThat(z.getFieldNames()).containsExactly("a", "b", "c", "d");
   }
 
   @Test
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleContextTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleContextTest.java
index 59b4b9a..f8b72ac 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleContextTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleContextTest.java
@@ -1618,7 +1618,6 @@
   }
 
   @Test
-  @SuppressWarnings("unchecked")
   public void testAccessingRunfilesSymlinks() throws Exception {
     scratch.file("test/a.py");
     scratch.file("test/b.py");
@@ -1712,7 +1711,6 @@
   }
 
   @Test
-  @SuppressWarnings("unchecked")
   public void testAccessingRunfilesRootSymlinks() throws Exception {
     scratch.file("test/a.py");
     scratch.file("test/b.py");
@@ -2415,7 +2413,6 @@
   }
 
   @Test
-  @SuppressWarnings("unchecked")
   public void testMapAttributeOrdering() throws Exception {
     scratch.file("a/a.bzl",
         "key_provider = provider(fields=['keys'])",