type diskHealthWrapper struct {
	tracker *healthDiskCtxValue
	r       io.Reader
	w       io.Writer
}

func (d *diskHealthWrapper) Read(p []byte) (int, error) {
	if d.r == nil {
		return 0, fmt.Errorf("diskHealthWrapper: Read with no reader")
	}
	n, err := d.r.Read(p)
	if err == nil || err == io.EOF && n > 0 {
		d.tracker.logSuccess()
	}
	return n, err
}

	mr      *msgp.Reader
	current metaCacheEntry
	err     error // stateful error
	closer  func()
	creator func() error
}

// newMetacacheReader creates a new cache reader.
// Nothing will be read from the stream yet.
func newMetacacheReader(r io.Reader) *metacacheReader {
	dec := s2DecPool.Get().(*s2.Reader)
	dec.Reset(r)
	mr := msgpNewReader(dec)
	return &metacacheReader{
		mr: mr,
		closer: func() {

# 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
```

/**
 * Result of a project build call.
 *
 * @since 4.0.0
 */
@Experimental
public interface ModelBuilderResult {

    /**
     * Gets the source from which the model was read.
     *
     * @return The source from which the model was read, never {@code null}.
     */
    @Nonnull
    ModelSource getSource();

    /**
     * Gets the file model.
     *
     * @return the file model, never {@code null}.
     */

```

::: fastapi.UploadFile
    options:
        members:
            - file
            - filename
            - size
            - headers
            - content_type
            - read
            - write
            - seek

                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        }
                    },
                    "summary": "Read Items",
                    "operationId": "read_items_items__get",
                    "x-aperture-labs-portal": "blue",
                }
            }
        },

                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        }
                    },
                    "summary": "Read Main",
                    "operationId": "read_main__get",
                }
            }
        },

///

## Other middlewares

You can later read more about other middlewares in the [Advanced User Guide: Advanced Middleware](../advanced/middleware.md){.internal-link target=_blank}.

    hashed_password: str


pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)

    hashed_password: str


pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)