val result = Buffer()

    while (pos < limit) {
      var dot = string.indexOf('.', startIndex = pos)
      if (dot == -1) dot = limit

      if (!encodeLabel(string, pos, dot, result)) {
        // If we couldn't encode the label, give up.
        return null
      }

      if (dot < limit) {
        result.writeByte('.'.code)
        pos = dot + 1
      } else {
        break
      }
    }

      ImmutableSet.of(
          "com",
          "co.uk",
          "foo.bd",
          "xxxxxx.bd",
          "org.mK",
          "us",
          "co.uk.", // Trailing dot
          "co\uFF61uk", // Alternate dot character
          "\u7f51\u7edc.Cn", // "网络.Cn"
          "j\u00f8rpeland.no", // "jorpeland.no" (first o slashed)
          "xn--jrpeland-54a.no"); // IDNA (punycode) encoding of above

      ImmutableSet.of(
          "com",
          "co.uk",
          "foo.bd",
          "xxxxxx.bd",
          "org.mK",
          "us",
          "co.uk.", // Trailing dot
          "co\uFF61uk", // Alternate dot character
          "\u7f51\u7edc.Cn", // "网络.Cn"
          "j\u00f8rpeland.no", // "jorpeland.no" (first o slashed)
          "xn--jrpeland-54a.no"); // IDNA (punycode) encoding of above

    # Exclude some linters from running on test files.
    - path: _test\.go$|^tests/|^samples/
      linters:
        - errcheck
        - maligned
    - path: _test\.go$
      text: "dot-imports: should not use dot imports"
    # We need to use the deprecated module since the jsonpb replacement is not backwards compatible.
    - linters:
        - staticcheck
      text: "SA1019: package github.com/golang/protobuf/jsonpb"

         * which to start, and using expressions split at the dot ('.') to navigate
         * the object graph beneath this root.
         * @param root the root of the graph.
         */
        public ObjectBasedValueSource(Object root) {
            super(true);
            this.root = root;
        }

        /**
         * <p>Split the expression into parts, tokenized on the dot ('.') character. Then,

<img src="/img/tutorial/extending-openapi/image03.png">

## Change the Theme

The same way you could set the syntax highlighting theme with the key `"syntaxHighlight.theme"` (notice that it has a dot in the middle):

```Python hl_lines="3"
{!../../../docs_src/configure_swagger_ui/tutorial002.py!}
```

That configuration would change the syntax highlighting color theme:

{!../../../docs_src/bigger_applications/app/routers/items.py!}
```

#### How relative imports work

!!! tip
    If you know perfectly how imports work, continue to the next section below.

A single dot `.`, like in:

```Python
from .dependencies import get_token_header
```

would mean:

  // IngressRuleValue. If the host is unspecified, the Ingress routes all
  // traffic based on the specified IngressRuleValue.
  //
  // host can be "precise" which is a domain name without the terminating dot of
  // a network host (e.g. "foo.bar.com") or "wildcard", which is a domain name
  // prefixed with a single wildcard label (e.g. "*.foo.com").
  // The wildcard character '*' must appear by itself as the first DNS label and

    // > There are 12 characters with special meanings:
    // > - the backslash \,
    // > - the caret ^,
    // > - the dollar sign $,
    // > - the period or dot .,
    // > - the vertical bar or pipe symbol |,
    // > - the question mark ?,
    // > - the asterisk or star *,
    // > - the plus sign +,
    // > - the opening parenthesis (,
    // > - the closing parenthesis ),

This practice is common enough that it has a name, these environment variables are commonly placed in a file `.env`, and the file is called a "dotenv".

!!! tip
    A file starting with a dot (`.`) is a hidden file in Unix-like systems, like Linux and macOS.

    But a dotenv file doesn't really have to have that exact filename.