refactor: use method reference without cast

src/main/java/com/github/nylle/javafixture/instantiation/BuilderInstantiator.java

@@ -35,7 +35,7 @@ public static <T> BuilderInstantiator<T> create(Method builderMethodCandidate, S
 
     private Map<BiFunction, Object> presetValues = new HashMap<>();
 
-    public BuilderInstantiator<T> with(BiFunction setter, Object value) {
+    public <U,V> BuilderInstantiator<T> with(BiFunction<U,V,U> setter, V value) {
         presetValues.put(setter, value);
         return this;
     }

src/test/java/com/github/nylle/javafixture/instantiation/BuilderInstantiatorTest.java

@@ -8,8 +8,6 @@
 import com.github.nylle.javafixture.testobjects.ClassWithBuilder;
 import org.junit.jupiter.api.Test;
 
-import java.util.function.BiFunction;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 class BuilderInstantiatorTest {
@@ -33,11 +31,9 @@ void builderCanBeCnfigured() throws NoSuchMethodException {
         var sut = BuilderInstantiator.create(ClassWithBuilder.class.getMethod("builder"), SpecimenType.fromClass(ClassWithBuilder.class));
 
         // we seem to need to explicitly cast it like this.
-        BiFunction<ClassWithBuilder.Builder, Integer, ClassWithBuilder.Builder> setter = ClassWithBuilder.Builder::number;
-        BiFunction<ClassWithBuilder.Builder, String, ClassWithBuilder.Builder> without = ClassWithBuilder.Builder::string;
         var result = sut
-                .with(setter, 2)
-                .with(without, null) // we have lambdas, i.e. no method names, so no without
+                .with(ClassWithBuilder.Builder::number, 2)
+                .with(ClassWithBuilder.Builder::string, null) // we have lambdas, i.e. no method names, so no without
                 .invoke(new SpecimenFactory(new Context(new Configuration())), CustomizationContext.noContext());
 
         assertThat(result).isInstanceOf(ClassWithBuilder.class);