method refs: simplify if first parameter is a receiver for method reference (IDEA-136882)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newMethodRef/SecondSearchIfFirstParameterIsASubtypeOfReferenceTypeFromExpressionDeclaration.java

@@ -0,0 +1,28 @@
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.function.Function;
+
+class Test {
+
+  static class Base {
+    public BigDecimal getTotal() {
+      return null;
+    }
+  }
+
+  public static void foo(List<? extends Base> list, List<Base> list1) {
+    System.out.println(add(list, Base::getTotal));
+    list1.forEach(Base::getTotal);
+  }
+
+
+  public static <T> BigDecimal add(Collection<T> objectsThatHaveBigDecimals, Function<T, ? extends BigDecimal> functionToGet) {
+    return objectsThatHaveBigDecimals == null ? null : objectsThatHaveBigDecimals.stream().map(functionToGet).reduce(null, Test::add);
+  }
+
+  public static BigDecimal add(BigDecimal... sequence) {
+    return null;
+  }
+}