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
      }
    }

<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: