Most of the standard headers are separated by a "hyphen" character, also known as the "minus symbol" (`-`).

But a variable like `user-agent` is invalid in Python.

So, by default, `Header` will convert the parameter names characters from underscore (`_`) to hyphen (`-`) to extract and document the headers.

                    return negotiate2(r);
                } else if (r.getDialectRevision() != Smb2Constants.SMB2_DIALECT_0202) {
                    throw new CIFSException("Server returned invalid dialect verison in multi protocol negotiation");
                }

                final int permits = r.getInitialCredits();
                if (permits > 0) {
                    this.credits.release(permits);

    }

    private void writeLittleEndianLong(DataOutputStream dos, long value) throws IOException {
        dos.writeLong(Long.reverseBytes(value));
    }

    @Test
    @DisplayName("Test parsing with invalid data size")
    void testInvalidDataSize() {
        byte[] tooSmall = new byte[10];

        PACDecodingException exception = assertThrows(PACDecodingException.class, () -> new PacLogonInfo(tooSmall));

	}

	newSSHCon := newSSHConnMock(accessKey + "=svc")
	_, err = sshPasswordAuth(newSSHCon, []byte("invalid"))
	if err == nil || !errors.Is(err, errAuthentication) {
		c.Fatalf("expected err(%s) but got (%s)", errAuthentication, err)
	}

	newSSHCon = newSSHConnMock(accessKey)
	_, err = sshPasswordAuth(newSSHCon, []byte("invalid"))
	if err == nil || !errors.Is(err, errAuthentication) {

            if (values.length > 2) {
                throw new InvalidQueryException(messages -> messages.addErrorsInvalidQuerySortValue(UserMessages.GLOBAL_PROPERTY_KEY, text),
                        "Invalid sort field: " + termQuery);
            }
            final String sortField = values[0];
            if (!getQueryFieldConfig().isSortField(sortField)) {
                throw new InvalidQueryException(

    /**
     * Retrieves an integer value from system properties with a default fallback.
     *
     * @param key the property key to look up
     * @param defaultValue the default value if the property is not found or invalid
     * @return the integer value or default value
     */
    protected Integer getDefaultInteger(final String key, final Integer defaultValue) {
        final String value = systemProperties.getProperty(key);

        // These tests validate current behavior where problematic paths are caught by other checks

        // Test invalid server name with dots - caught by directory traversal check
        assertThrows(SmbException.class, () -> {
            validator.validatePath("\\\\..\\share");
        });

        // Test invalid characters in paths - caught by null byte check
        assertThrows(SmbException.class, () -> {

        boolean result = filter.accept(mockDir, name);

        assertEquals(expected, result, "Filter should evaluate .txt suffix correctly");
        verifyNoInteractions(mockDir);
    }

    /**
     * Invalid/null inputs: ensure filters can handle null name and dir.
     */
    @ParameterizedTest
    @DisplayName("null and empty names are handled explicitly")
    @NullAndEmptySource
    @ValueSource(strings = { " \t\n" })

   *
   * @since 12.0
   */
  void putAll(Map<? extends K, ? extends V> m);

  /** Discards any cached value for key {@code key}. */
  void invalidate(@CompatibleWith("K") Object key);

  /**
   * Discards any cached values for keys {@code keys}.
   *
   * @since 11.0
   */
  // For discussion of <? extends Object>, see getAllPresent.

Con solo esa declaración de tipo en Python, **FastAPI** hará lo siguiente:

* Leer el body del request como JSON.
* Convertir los tipos correspondientes (si es necesario).
* Validar los datos.
    * Si los datos son inválidos, devolverá un error claro e indicado, señalando exactamente dónde y qué fue lo incorrecto.
* Proporcionar los datos recibidos en el parámetro `item`.