is_coroutine = dependant.is_coroutine_callable
    is_body_form = body_field and isinstance(body_field.field_info, params.Form)
    if isinstance(response_class, DefaultPlaceholder):
        actual_response_class: type[Response] = response_class.value
    else:
        actual_response_class = response_class
    is_sse_stream = lenient_issubclass(actual_response_class, EventSourceResponse)
    if isinstance(strict_content_type, DefaultPlaceholder):

class PNGStreamingResponse(StreamingResponse):
    media_type = "image/png"


@app.get("/image/stream", response_class=PNGStreamingResponse)
async def stream_image() -> AsyncIterable[bytes]:
    with read_image() as image_file:
        for chunk in image_file:
            yield chunk


@app.get("/image/stream-no-async", response_class=PNGStreamingResponse)
def stream_image_no_async() -> Iterable[bytes]:
    with read_image() as image_file:

]


app = FastAPI()


@app.get("/items/stream", response_class=EventSourceResponse)
async def sse_items() -> AsyncIterable[Item]:
    for item in items:
        yield item


@app.get("/items/stream-sync", response_class=EventSourceResponse)
def sse_items_sync() -> Iterable[Item]:
    yield from items


@app.get("/items/stream-no-annotation", response_class=EventSourceResponse)
async def sse_items_no_annotation():

def get_b_path_override():
    return "Hello B"


@router_b_a.get("/")
def get_b_a():
    return "Hello B A"


@router_b_a.get("/override", response_class=HTMLResponse)
def get_b_a_path_override():
    return "Hello B A"


@router_b_a_c_override.get("/")
def get_b_a_c():
    return "Hello B A C"


@router_b_a_c_override.get("/override", response_class=OverrideResponse)

## Stream bytes

To stream bytes, declare a `response_class=` of `StreamingResponse` or a sub-class, and use `yield` to return the data.

```python
from fastapi import FastAPI
from fastapi.responses import StreamingResponse
from app.utils import read_image

app = FastAPI()


class PNGStreamingResponse(StreamingResponse):
    media_type = "image/png"

@app.get("/image", response_class=PNGStreamingResponse)

@app.get("/story/stream-no-annotation", response_class=StreamingResponse)
async def stream_story_no_annotation():
    for line in message.splitlines():
        yield line


@app.get("/story/stream-no-async-no-annotation", response_class=StreamingResponse)
def stream_story_no_async_no_annotation():
    for line in message.splitlines():
        yield line


@app.get("/story/stream-bytes", response_class=StreamingResponse)

def get_b_path_override():
    return "Hello B"


@router_b_a.get("/")
def get_b_a():
    return "Hello B A"


@router_b_a.get("/override", response_class=HTMLResponse)
def get_b_a_path_override():
    return "Hello B A"


@router_b_a_c_override.get("/")
def get_b_a_c():
    return "Hello B A C"


@router_b_a_c_override.get("/override", response_class=OverrideResponse)

{* ../../docs_src/response_model/tutorial001_01_py310.py ln[15:17] hl[16] *}

## HTML Response { #html-response }

To return a response with HTML directly from **FastAPI**, use `HTMLResponse`.

* Import `HTMLResponse`.
* Pass `HTMLResponse` as the parameter `response_class` of your *path operation decorator*.

]


@app.get("/items/stream", response_class=EventSourceResponse)
async def sse_items() -> AsyncIterable[Item]:
    for item in items:
        yield item


@app.get("/items/stream-no-async", response_class=EventSourceResponse)
def sse_items_no_async() -> Iterable[Item]:
    for item in items:
        yield item


@app.get("/items/stream-no-annotation", response_class=EventSourceResponse)

    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():