* The logic can be shared by multiple endpoints to do things like error early, authentication, etc.
* They need to handle cleanup (e.g., DB sessions, file handles), using dependencies with `yield`
* Their logic needs input data from the request, like headers, query parameters, etc.

## Dependencies with `yield` and `scope`

When using dependencies with `yield`, they can have a `scope` that defines when the exit code is run.

        result = netShareEnum.writeSetupWireFormat(dst, 50);
        assertEquals(0, result);

        // Verify no data was written
        assertArrayEquals(new byte[100], dst);
    }

    @Test
    @DisplayName("Test writeParametersWireFormat writes correct data")
    void testWriteParametersWireFormat() throws Exception {
        netShareEnum = new NetShareEnum(realConfig);

package cmd

import (
	"context"
	"fmt"
	"io"
)

// Writes to multiple writers
type multiWriter struct {
	writers     []io.Writer
	writeQuorum int
	errs        []error
}

// Write writes data to writers.
func (p *multiWriter) Write(ctx context.Context, blocks [][]byte) error {
	for i := range p.writers {
		if p.errs[i] != nil {
			continue
		}
		if p.writers[i] == nil {
			p.errs[i] = errDiskNotFound

    void setGetMechanismToken() {
        TestSpnegoToken t = new TestSpnegoToken();
        byte[] data = new byte[] { 1, 2, 3 };
        t.setMechanismToken(data);
        assertArrayEquals(data, t.getMechanismToken(), "mechanismToken should round-trip");

        // Document current behavior: no defensive copy (reference exposed)
        data[0] = 9;
        assertEquals(9, t.getMechanismToken()[0], "no defensive copy; reflects external mutation");

    }

    int getCount() {
      return count;
    }
  }

  /** Returns the file holding the data (possibly null). */
  @VisibleForTesting
  @Nullable File getFile() {
    return state.getFile();
  }

  /**
   * Creates a new instance that uses the given file threshold, and does not reset the data when the
   * {@link ByteSource} returned by {@link #asByteSource} is garbage collected.
   *

        // Arrange
        byte[] data = new byte[] { (byte) 0xDE, (byte) 0xAD, (byte) 0xBE, (byte) 0xEF };

        // Act
        SecurityBlob blob = new SecurityBlob(data);

        // Assert
        assertSame(data, blob.get(), "get() should expose the same array reference passed in");
        assertEquals(data.length, blob.length(), "length() should match underlying array length");

It will perform the validation of the compound data, and will document it like that for the OpenAPI schema and automatic docs.

## Singular values in body { #singular-values-in-body }

The same way there is a `Query` and `Path` to define extra data for query and path parameters, **FastAPI** provides an equivalent `Body`.

          const string& v = default_value.list().s(i);
          values_vector.push_back(v.data());
          lengths_vector.push_back(v.size());
        }
        TFE_OpSetAttrStringList(op, attr_name, values_vector.data(),
                                lengths_vector.data(), s_size);
      }

      // Int
      if (const int i_size = default_value.list().i_size()) {

		return
	}

	// Encode result and send response.

	data, err := json.Marshal(res)
	if err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}
	password := cred.SecretKey
	econfigData, err := madmin.EncryptData(password, data)
	if err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}

                                                            <la:message key="labels.file_auth_any"/>
                                                        </c:if> ${f:h(data.hostname)}: <c:if
                                                                test="${data.port==null||data.port==''}">