* Import `Jinja2Templates`.
* Create a `templates` object that you can re-use later.
* Declare a `Request` parameter in the *path operation* that will return a template.
* Use the `templates` you created to render and return a `TemplateResponse`, pass the name of the template, the request object, and a "context" dictionary with key-value pairs to be used inside of the Jinja2 template.

```Python hl_lines="4  11  15-18"

    Read more about it in the
    [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/).
    """

    def render(self, content: Any) -> bytes:
        assert ujson is not None, "ujson must be installed to use UJSONResponse"
        return ujson.dumps(content, ensure_ascii=False).encode("utf-8")


class ORJSONResponse(JSONResponse):

      placeholder: Tell us what you see!
      value:
      render: shell
    validations:
      required: true
  - type: textarea
    id: logs
    attributes:
      label: Relevant log output
      description: Please copy and paste any relevant log output. This will be automatically formatted into code, so no need for backticks.

from typing import Any

import orjson
from fastapi import FastAPI, Response

app = FastAPI()


class CustomORJSONResponse(Response):
    media_type = "application/json"

    def render(self, content: Any) -> bytes:
        assert orjson is not None, "orjson must be installed"
        return orjson.dumps(content, option=orjson.OPT_INDENT_2)


@app.get("/", response_class=CustomORJSONResponse)
async def main():

# Templating - `Jinja2Templates`

You can use the `Jinja2Templates` class to render Jinja templates.

Read more about it in the [FastAPI docs for Templates](https://fastapi.tiangolo.com/advanced/templates/).

You can import it directly from `fastapi.templating`:

```python
from fastapi.templating import Jinja2Templates
```

  - type: textarea
    attributes:
      label: API(s)
      description: Which existing classes or methods do you want to improve?
      placeholder: e.g., `com.google.common.collect.ImmutableList::of`
      render: java
    validations:
      required: true

  - type: textarea
    attributes:
      label: How do you want it to be improved?
    validations:
      required: true

  - type: textarea
    attributes:

    addFinish() {
        const finish = this.generateFinish()
        this.container.appendChild(finish)
    }

    /**
     * Animate a typed line.
     * @param {Node} line - The line element to render.
     */
    async type(line) {
        const chars = [...line.textContent];
        line.textContent = '';
        this.container.appendChild(line);

        for (let char of chars) {

        get() = withValidityAssertion {
            val diagnostic = firDiagnostic as KtDiagnostic

            val firDiagnosticRenderer = RootDiagnosticRendererFactory(diagnostic)
            return firDiagnosticRenderer.render(diagnostic)
        }

    override val textRanges: Collection<TextRange>
        get() = withValidityAssertion { firDiagnostic.textRanges }

    @Suppress("UNCHECKED_CAST")
    override val psi: PSI

}

// generateValidatingWebhook renders a validating webhook configuration from the given tagWebhookConfig.
func generateValidatingWebhook(config *tagWebhookConfig, opts *GenerateOptions) (string, error) {
	r := helm.NewHelmRenderer(opts.ManifestsPath, defaultChart, "Pilot", config.IstioNamespace, nil)

	if err := r.Run(); err != nil {
		return "", fmt.Errorf("failed running Helm renderer: %v", err)
	}

	values := fmt.Sprintf(`

import org.jetbrains.kotlin.analysis.api.fir.generator.printTypeWithShortNames
import org.jetbrains.kotlin.utils.SmartPrinter

object KtDiagnosticClassRenderer : AbstractDiagnosticsDataClassRenderer() {
    override fun SmartPrinter.render(diagnosticList: HLDiagnosticList, packageName: String) {
        printHeader(packageName, diagnosticList)
        printDiagnosticClasses(diagnosticList)
    }