Test case for #1528 (#1556)

Fixes #1528 

Add a test case to ensure we handle this case correctly.


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Tests**
* Added regression test to enhance validation of nullability inference
with generic method type parameters and method references. The test
specifically covers stream operations combined with wildcard type
parameters, strengthening test coverage for complex type inference
scenarios and improving overall quality assurance.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: msridhar

nullaway/src/test/java/com/uber/nullaway/jspecify/GenericMethodLambdaOrMethodRefArgTests.java

@@ -963,6 +963,48 @@ static Map<String,String> test(Map<String,String> map) {
         .doTest();
   }
 
+  @Test
+  public void issue1528() {
+    makeHelperWithInferenceFailureWarning()
+        .addSourceLines(
+            "Test.java",
+            """
+            import org.jspecify.annotations.NullMarked;
+            import org.jspecify.annotations.Nullable;
+            import java.util.Map;
+            import java.util.function.Function;
+            import java.util.stream.Stream;
+            @NullMarked
+            class Test {
+              <T> Test and(Stream<T> stream, Function<T, @Nullable Pair> mapper) {
+                return this;
+              }
+              static class Pair {
+                private final String name;
+                private final @Nullable String value;
+                private Pair(String name, @Nullable String value) {
+                  this.name = name;
+                  this.value = value;
+                }
+                static Pair fromMapEntry(Map.Entry<String, @Nullable String> entry) {
+                  return new Pair(entry.getKey(), entry.getValue());
+                }
+                static Pair fromMapEntryWildcard(Map.Entry<String, ? extends @Nullable String> entry) {
+                  return new Pair(entry.getKey(), entry.getValue());
+                }
+              }
+              Test and(Map<String, String> map) {
+                // BUG: Diagnostic contains: parameter type of referenced method is Entry<String, @Nullable String>
+                return and(map.entrySet().stream(), Pair::fromMapEntry);
+              }
+              Test andWildcard(Map<String, String> map) {
+                return and(map.entrySet().stream(), Pair::fromMapEntryWildcard);
+              }
+            }
+            """)
+        .doTest();
+  }
+
   @Test
   public void genericMethodLambdaArgWildCard() {
     makeHelperWithInferenceFailureWarning()