This can be very useful for setting up **resources** that you need to use for the whole app, and that are **shared** among requests, and/or that you need to **clean up** afterwards. For example, a database connection pool, or loading a shared machine learning model.

## Use Case { #use-case }

Let's start with an example **use case** and then see how to solve it with this.

Pode ser muito útil para configurar **recursos** que você precisa usar por toda aplicação, e que são **compartilhados** entre as requisições, e/ou que você precisa **limpar** depois. Por exemplo, o pool de uma conexão com o banco de dados ou carregamento de um modelo compartilhado de aprendizado de máquina (_machine learning_).

## Caso de uso

Vamos iniciar com um exemplo de **caso de uso** e então ver como resolvê-lo com isso.

				expr.Vars = append(expr.Vars, clause.AndConditions{Exprs: j.On.Exprs})
			}

			j.Expression = expr
		}

		db.Statement.Joins = append(db.Statement.Joins, j)
		sort.Slice(db.Statement.Joins, func(i, j int) bool {
			return db.Statement.Joins[i].Name < db.Statement.Joins[j].Name
		})
		return db
	})
}

func (c chainG[T]) Select(query string, args ...interface{}) ChainInterface[T] {
	return c.with(func(db *DB) *DB {

			})
		if err != nil {
			t.Fatalf("Erasure Object upload failed: <ERROR> %s", err)
		}
		versions[i] = objInfo.VersionID
	}

	// Remove and check the version in the second pool, then
	// remove and check the version in the first pool
	for testIdx, vid := range []string{versions[1], versions[0]} {
		names := []ObjectToDelete{
			{
				ObjectV: ObjectV{
					ObjectName: objectName,
					VersionID:  vid,
				},

    }

    public void bool(BoolCall<JobLogCQ> boolLambda) {
        bool(boolLambda, null);
    }

    public void bool(BoolCall<JobLogCQ> boolLambda, ConditionOptionCall<BoolQueryBuilder> opLambda) {
        JobLogCQ mustQuery = new JobLogCQ();
        JobLogCQ shouldQuery = new JobLogCQ();
        JobLogCQ mustNotQuery = new JobLogCQ();
        JobLogCQ filterQuery = new JobLogCQ();

	SubSys          string         `json:"subSys"`
	Description     string         `json:"description"`
	MultipleTargets bool           `json:"multipleTargets"`
	KeysHelp        config.HelpKVS `json:"keysHelp"`
}

// GetHelp - returns help for sub-sys, a key for a sub-system or all the help.
func GetHelp(subSys, key string, envOnly bool) (Help, error) {
	if len(subSys) == 0 {
		return Help{KeysHelp: config.HelpSubSysMap[subSys]}, nil
	}

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):

    @Override
    int writeDataWireFormat(final byte[] dst, final int dstIndex) {
        if (dst.length - dstIndex < pipeDataLen) {
            if (LogStream.level >= 3) {
                log.println("TransCallNamedPipe data too long for buffer");
            }
            return 0;
        }
        System.arraycopy(pipeData, pipeDataOff, dst, dstIndex, pipeDataLen);
        return pipeDataLen;
    }

    @Override

		opts.HasIfMatch = true
	}
	if opts.PreserveETag != "" ||
		r.Header.Get(xhttp.IfMatch) != "" ||
		r.Header.Get(xhttp.IfNoneMatch) != "" {
		opts.CheckPrecondFn = func(oi ObjectInfo) bool {
			if _, err := DecryptObjectInfo(&oi, r); err != nil {
				writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
				return true
			}
			return checkPreconditionsPUT(ctx, w, r, oi, opts)
		}
	}

   * insists upon doing. It then runs the test, which behaves exactly like this package's existing
   * PackageSanityTests. (The test would run on the JVM, too, if not for the suppression below, and
   * that would be a problem because it violates small-test rules. Note that we strip the
   * suppression externally, but it's OK because we don't enforce test-size rules there.)
   *