brilianfird

    @Test
    public void initializeOptional_optionalOf() {
        Optional<String> helloWorldOptional = Optional.of("Hello, world");
        assert helloWorldOptional.isPresent();
        assert "Hello, world".equals(helloWorldOptional.get());
    }

brilianfird

    public SimpleStream<T> map(Function<T, T> function) {
        List<T> returnValueList = new ArrayList<>();
        for (T value : values) {
            returnValueList.add(value + " String");
        }
        this.values = returnValueList;
        return this;
    }

brilianfird

package com.example.functional.programming.intf;

import com.example.functional.programming.model.Person;

@FunctionalInterface
public interface PersonFunctionalInterface {

    Person createPerson(String name);

    default String getDefaultMethodString() {

brilianfird

package com.example.functional.programming.model;

public class Person {

    private String name;

    public String getName() {
        return name;
    }