t.Fatalf("no error should happen when migrate scanner, valuer struct, got error %v", err)
	}

	data := ScannerValuerStruct{
		Name:     sql.NullString{String: "name", Valid: true},
		Gender:   &sql.NullString{String: "M", Valid: true},
		Age:      sql.NullInt64{Int64: 18, Valid: true},
		Male:     sql.NullBool{Bool: true, Valid: true},
		Height:   sql.NullFloat64{Float64: 1.8888, Valid: true},

      }
    }
  }

  private enum Gender {
    MALE,
    FEMALE
  }

  private static class AllDefaultValuesChecker extends DefaultValueChecker {

    @SuppressWarnings("unused") // called by NullPointerTester
    public void checkDefaultValuesForTheseTypes(
        Gender gender,
        Integer integer,
        int i,
        String string,

Но внутреннее устройство **конкурентности** и **параллелизма** довольно разное.

Чтобы это понять, представьте такую картину:

### Конкурентные бургеры

<!-- The gender neutral cook emoji "🧑‍🍳" does not render well in browsers. In the meantime, I'm using a mix of male "👨‍🍳" and female "👩‍🍳" cooks. -->

/*
 * Copyright (C) 2010 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

	"strconv"
	"strings"
	"time"
)

// Reader provides sequential access to the contents of a tar archive.
// Reader.Next advances to the next file in the archive (including the first),
// and then Reader can be treated as an io.Reader to access the file's data.
type Reader struct {
	r    io.Reader
	pad  int64      // Amount of padding (ignored) after current file entry
	curr fileReader // Reader for current file entry

)

// A Reader wraps an io.Reader and computes the MD5 checksum
// of the read content as ETag. Optionally, it also computes
// the SHA256 checksum of the content.
//
// If the reference values for the ETag and content SHA26
// are not empty then it will check whether the computed
// match the reference values.
type Reader struct {
	src         io.Reader
	bytesRead   int64
	expectedMin int64

// the [ErrInsecurePath] error and use the returned reader.
func NewReader(r io.ReaderAt, size int64) (*Reader, error) {
	if size < 0 {
		return nil, errors.New("zip: size cannot be negative")
	}
	zr := new(Reader)
	var err error
	if err = zr.init(r, size); err != nil && err != ErrInsecurePath {
		return nil, err
	}
	return zr, err
}

func (r *Reader) init(rdr io.ReaderAt, size int64) error {

### Typannotationen und Tooling

Sehen wir uns zunächst an, wie Editor, mypy und andere Tools dies sehen würden.

`BaseUser` verfügt über die Basis-Felder. Dann erbt `UserIn` von `BaseUser` und fügt das Feld `Passwort` hinzu, sodass dass es nun alle Felder beider Modelle hat.

Wir annotieren den Funktionsrückgabetyp als `BaseUser`, geben aber tatsächlich eine `UserIn`-Instanz zurück.

import org.jetbrains.kotlin.name.FqName
import org.jetbrains.kotlin.name.SpecialNames
import org.jetbrains.kotlin.name.StandardClassIds
import org.jetbrains.kotlin.renderer.DescriptorRenderer
import org.jetbrains.kotlin.renderer.render
import org.jetbrains.kotlin.resolve.calls.inference.CapturedType
import org.jetbrains.kotlin.resolve.descriptorUtil.annotationClass
import org.jetbrains.kotlin.types.*
import org.jetbrains.kotlin.types.checker.NewCapturedType

		if Requested(test.Header) != got {
			// Test if result matches.
			t.Errorf("Requested mismatch, want %v, got %v", Requested(test.Header), got)
		}
		got = got && SSEC.IsRequested(test.Header)
		if got != test.Expected {
			t.Errorf("SSE-C: Test %d: Wanted %v but got %v", i, test.Expected, got)
		}
	}
}

var kmsIsRequestedTests = []struct {
	Header   http.Header
	Expected bool
}{