### Certificate Renewal { #certificate-renewal }

At some point in the future, each certificate would **expire** (about 3 months after acquiring it).

And then, there would be another program (in some cases it's another program, in some cases it could be the same TLS Termination Proxy) that would talk to Let's Encrypt, and renew the certificate(s).

        checkNotBinaryCompatibleKotlin(
            v1 = """
                class Source(some: String?) {
                    var someVar: String? = null
                    fun foo(bar: String?) {}
                }
            """,
            v2 = """
                class Source(some: String) {
                    var someVar: String = "some"
                    fun foo(bar: String) {}
                }
            """

**projects depend on**. That's very difficult to manage. And you would probably end up running some projects with some **incompatible versions** of the packages, and not knowing why something isn't working.

Also, depending on your operating system (e.g. Linux, Windows, macOS), it could have come with Python already installed. And in that case it probably had some packages pre-installed with some specific versions **needed by your system**. If you install packages in the global Python environment,...

//// tab | Test

/// info
Some text
///

/// note
Some text
///

/// note | Technical details
Some text
///

/// check
Some text
///

/// tip
Some text
///

/// warning
Some text
///

/// danger
Some text
///

////

//// tab | Info

newThing = objects.newInstance(NewThing.class)
newThing.convention("some-value")
```

This is acceptable for existing things:

```groovy
public interface ExistingThing {
    Property<String> getSomeProperty()
}

abstract class DefaultExistingThing implements ExistingThing {
    DefaultExistingThing() {
        getSomeProperty().convention("some-value")
    }
}

// in plugin

import (
	"archive/tar"
	"bytes"
	"fmt"
	"io"
	"log"
	"os"
)

func Example_minimal() {
	// Create and add some files to the archive.
	var buf bytes.Buffer
	tw := tar.NewWriter(&buf)
	var files = []struct {
		Name, Body string
	}{
		{"readme.txt", "This archive contains some text files."},
		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
		{"todo.txt", "Get animal handling license."},
	}

The **Advanced User Guide** builds on this one, uses the same concepts, and teaches you some extra features.

But you should first read the **Tutorial - User Guide** (what you are reading right now).

        * `implicit`
        * `clientCredentials`
        * `authorizationCode`
    * But there is one specific "flow" that can be perfectly used for handling authentication in the same application directly:
        * `password`: some next chapters will cover examples of this.
* `openIdConnect`: has a way to define how to discover OAuth2 authentication data automatically.

        new File("/home/build/x/y/z.jar").toURI(),
        ClassPath.getClassPathEntry(new File("/home/build/outer.jar"), "x/y/z.jar").toURI());
    assertEquals(
        "/home/build/x y.jar",
        ClassPath.getClassPathEntry(new File("/home/build/outer.jar"), "x y.jar").getFile());
  }

  public void testGetClassPathFromManifest_nullManifest() {
    assertThat(ClassPath.getClassPathFromManifest(new File("some.jar"), null)).isEmpty();
  }

-Dorg.gradle.daemon.idletimeout=120000 -Dorg.gradle.daemon.registry.base=C:\\some\\agent\\workspace\\build\\daemon -Dorg.gradle.native.dir=C:\\some\\agent\\workspace\\intTestHomeDir\\worker-1\\native -Dorg.gradle.deprecation.trace=true -Djava.io.tmpdir=C:\\some\\agent\\workspace\\subprojects\\osgi\\build\\tmp -Dfile.encoding=windows-1252 -Dorg.gradle.classloaderscope.strict=true -ea -ea "-Dorg.gradle.appname=gradle" -classpath "C:\\some\\agent\\workspace\\subprojects\\osgi\\build\\integ test\\bin\\..\\li...