analyzer, which flags references to symbols that are too new for the version
of Go in effect in the referring file. (The effective version is determined
by the `go` directive in the file's enclosing `go.mod` file, and
by any [`//go:build` constraints](https://pkg.go.dev/cmd/go#hdr-Build_constraints)
in the file.)

For example, it will report a diagnostic for a reference to the

	// Storage class is special, it can be replaced regardless of the
	// metadata directive, if set should be preserved and replaced
	// to the destination metadata.
	sc := r.Header.Get(xhttp.AmzStorageClass)
	if sc == "" {
		sc = r.Form.Get(xhttp.AmzStorageClass)
	}

	// if x-amz-metadata-directive says REPLACE then
	// we extract metadata from the input headers.

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidMetadataDirective: {
		Code:           "InvalidArgument",
		Description:    "Unknown metadata directive.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidStorageClass: {
		Code:           "InvalidStorageClass",
		Description:    "Invalid storage class.",
		HTTPStatusCode: http.StatusBadRequest,
	},

			req.Header.Set(k, v)
		}
		if testCase.metadataReplace {
			req.Header.Set("X-Amz-Metadata-Directive", "REPLACE")
		}
		if testCase.metadataCopy {
			req.Header.Set("X-Amz-Metadata-Directive", "COPY")
		}
		if testCase.metadataGarbage {
			req.Header.Set("X-Amz-Metadata-Directive", "Unknown")
		}
		// Since `apiRouter` satisfies `http.Handler` it has a ServeHTTP to execute the logic of the handler.

interface{ chan int | chan<- string }     // channels have different element types
interface{ <-chan int | chan<- int }      // directional channels have different directions
</pre>

<p>
Some operations (<a href="#Slice_expressions">slice expressions</a>,
<a href="#Appending_and_copying_slices"><code>append</code> and <code>copy</code></a>)

    "1" also makes cuDNN convolution and max-pooling operate deterministically.
    This makes Keras Conv\*D and MaxPool\*D layers operate deterministically in
    both the forward and backward directions when running on a CUDA-enabled GPU.

## Breaking Changes

*   Deletes `Operation.traceback_with_start_lines` for which we know of no
    usages.