*
   * <p>This fit minimizes the root-mean-square error in {@code y} as a function of {@code x}. This
   * error is defined as the square root of the mean of the squares of the differences between the
   * actual {@code y} values of the data and the values predicted by the fit for the {@code x}
   * values (i.e. it is the square root of the mean of the squares of the vertical distances between

{!../../docs_src/python_types/tutorial009.py!}
```

Using `Optional[str]` instead of just `str` will let the editor help you detect errors where you could be assuming that a value is always a `str`, when it could actually be `None` too.

`Optional[Something]` is actually a shortcut for `Union[Something, None]`, they are equivalent.

This also means that in Python 3.10, you can use `Something | None`:

//// tab | Python 3.10+

```Python hl_lines="1"

)

const (
	// MaxScanTokenSize is the maximum size used to buffer a token
	// unless the user provides an explicit buffer with [Scanner.Buffer].
	// The actual maximum token size may be smaller as the buffer
	// may need to include, for instance, a newline.
	MaxScanTokenSize = 64 * 1024

	startBufSize = 4096 // Size of initial allocation for buffer.
)

                       const std::unordered_set<string>& nodes) {
    ASSERT_EQ(nodes.size(), fdef.node_def_size())
        << "Got unexpected number of nodes. Expected: ["
        << absl::StrJoin(nodes, ", ")
        << "] Actual nodes in fdef: " << fdef.DebugString();
    for (const NodeDef& node_def : fdef.node_def()) {
      ASSERT_TRUE(nodes.find(node_def.name()) != nodes.end())
          << "Got unexpected node: " << node_def.name()

				CalculatedSHA256: "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
			},
		},
		// Test case - 14.
		// Input with size more than the size of actual data inside the reader.
		{
			bucketName: bucket, objName: object, uploadID: uploadID, PartID: 1, inputReaderData: "abcd", inputMd5: "e2fc714c4727ee9395f324cd2e7f3335", inputDataSize: int64(len("abcd") + 1),

	// the diskWithAllParts needs to reach the drive to ensure
	// validity of the metadata content, we should make sure that
	// we pass in disks as is for it to be verified. Once verified
	// the disksWithAllParts() returns the actual disks that can be
	// used here for reconstruction. This is done to ensure that
	// we do not skip drives that have inconsistent metadata to be
	// skipped from purging when they are stale.

 * @since 16.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class MultimapBuilder<K0 extends @Nullable Object, V0 extends @Nullable Object> {
  /*
   * Leaving K and V as upper bounds rather than the actual key and value types allows type
   * parameters to be left implicit more often. CacheBuilder uses the same technique.
   */

  private MultimapBuilder() {}

  private static final int DEFAULT_EXPECTED_KEYS = 8;

   * up the necessary in-memory cache information.
   *
   * The initialization time may vary depending on the journal file size and the current actual
   * cache size. The application needs to be aware of calling this function during the
   * initialization phase and preferably in a background worker thread.
   *

				return key
			}
		}
	}
	if _, ok := r.Header[xhttp.MinIOSourceReplicationRequest]; ok {
		opts.ReplicationRequest = true
		opts.UserDefined[ReservedMetadataPrefix+"Actual-Object-Size"] = r.Header.Get(xhttp.MinIOReplicationActualObjectSize)
	}
	if r.Header.Get(ReplicationSsecChecksumHeader) != "" {
		opts.UserDefined[ReplicationSsecChecksumHeader] = r.Header.Get(ReplicationSsecChecksumHeader)

in connection with its distribution of the Program in a commercial product
offering. The obligations in this section do not apply to any claims or Losses
relating to any actual or alleged intellectual property infringement. In order
to qualify, an Indemnified Contributor must: a) promptly notify the Commercial
Contributor in writing of such claim, and b) allow the Commercial Contributor