### Context variables

Python 3.7 has <a href="https://docs.python.org/3/library/contextvars.html" class="external-link" target="_blank">`contextvars`</a> that can create a local variable very similar to `threading.local`, but also supporting these async features.

There are several things to keep in mind.

The `ContextVar` has to be created at the top of the module, like:

```Python
some_var = ContextVar("some_var", default="default value")

One of those distributed container management systems like Kubernetes normally has some integrated way of handling **replication of containers** while still supporting **load balancing** for the incoming requests. All at the **cluster level**.

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import javax.annotation.CheckForNull;

/**
 * A synchronization abstraction supporting waiting on arbitrary boolean conditions.
 *
 * <p>This class is intended as a replacement for {@link ReentrantLock}. Code using {@code Monitor}

// still called on `device_info` (i.e. the caller does not retain ownership).
//
// This API is highly experimental, and in particular is expected to change when
// it starts supporting operations with attributes and when tf.function support
// is added.
TF_CAPI_EXPORT extern void TFE_RegisterCustomDevice(TFE_Context* ctx,
                                                    TFE_CustomDevice device,

agent) that runs one, and only one, pod per node.
     * TLS and L7 support (Ingress API (Beta) in the Extensions API group): Kubernetes
is now easier to integrate into custom networking environments by supporting
TLS for secure communication and L7 http-based traffic routing.
     * Graceful Node Shutdown (aka drain) - The new “kubectl drain” command gracefully
evicts pods from nodes in preparation for disruptive operations like kernel

### SIG-Azure

Sig Azure was focused on two primary new alpha features:
- Adding Azure Availability Zones support to cloud provider.
- Supporting Cross RG resources (disks, Azure File and node [Experimental]

Besides the above new features, support for Azure Virtual Machine Scale Sets (VMSS) and Cluster-Autoscaler is now stable and considered GA:

Instead, it collects all the Go code and writes a single go.o object
file containing it. Then it invokes the host linker (usually gcc) to
combine the go.o object file and any supporting non-Go code into a
final executable. External linking avoids the dynamic library
requirement but introduces a requirement that the host linker be
present to create such a binary.

## Version 3.12.10

_2020-02-29_

 *  Fix: Don't crash on Android 4.1 when detecting methods that became restricted in Android 11.
    Supporting a full decade of Android releases on our 3.12.x branch is tricky!


## Version 3.12.9

_2020-02-24_

 *  Fix: Don't crash on Android 11 due to use of restricted methods. This prevents a crash with the

	}
	req.Header.Set("x-amz-content-sha256", hashedPayload)

	// Add Content-Length
	req.ContentLength = contentLength

	return req, nil
}

// Various signature types we are supporting, currently
// two main signature types.
type signerType int

const (
	signerV2 signerType = iota
	signerV4
)

			encStream.Close()
			stream.AddError(msg)
		}
		defer encStream.Close()

		inspectZipW = zip.NewWriter(encStream)
		defer inspectZipW.Close()
	} else {
		// Legacy: Remove if we stop supporting inspection without public key.
		var key [32]byte
		// MUST use crypto/rand
		n, err := crand.Read(key[:])
		if err != nil || n != len(key) {
			bugLogIf(ctx, err)