{* ../../docs_src/query_params_str_validations/tutorial004.py hl[10] *}

Cette expression régulière vérifie que la valeur passée comme paramètre :

* `^` : commence avec les caractères qui suivent, avec aucun caractère avant ceux-là.

`Header` tem algumas funcionalidades a mais em relação a `Path`, `Query` e `Cookie`.

A maioria dos cabeçalhos padrão são separados pelo caractere "hífen", também conhecido como "sinal de menos" (`-`).

Mas uma variável como `user-agent` é inválida em Python.

Portanto, por padrão, `Header` converterá os caracteres de nomes de parâmetros de sublinhado (`_`) para hífen (`-`) para extrair e documentar os cabeçalhos.

      into.putBytes(from);
    }

    @Override
    public String toString() {
      return "Funnels.byteArrayFunnel()";
    }
  }

  /**
   * Returns a funnel that extracts the characters from a {@code CharSequence}, a character at a
   * time, without performing any encoding. If you need to use a specific encoding, use {@link
   * Funnels#stringFunnel(Charset)} instead.
   *

      into.putBytes(from);
    }

    @Override
    public String toString() {
      return "Funnels.byteArrayFunnel()";
    }
  }

  /**
   * Returns a funnel that extracts the characters from a {@code CharSequence}, a character at a
   * time, without performing any encoding. If you need to use a specific encoding, use {@link
   * Funnels#stringFunnel(Charset)} instead.
   *

import java.util.List;
import java.util.function.Consumer;
import java.util.stream.Stream;
import org.jspecify.annotations.Nullable;

/**
 * A readable source of characters, such as a text file. Unlike a {@link Reader}, a {@code
 * CharSource} is not an open, stateful stream of characters that can be read and closed. Instead,
 * it is an immutable <i>supplier</i> of {@code Reader} instances.
 *
 * <p>{@code CharSource} provides two kinds of methods:
 *

import java.util.List;
import java.util.function.Consumer;
import java.util.stream.Stream;
import org.jspecify.annotations.Nullable;

/**
 * A readable source of characters, such as a text file. Unlike a {@link Reader}, a {@code
 * CharSource} is not an open, stateful stream of characters that can be read and closed. Instead,
 * it is an immutable <i>supplier</i> of {@code Reader} instances.
 *
 * <p>{@code CharSource} provides two kinds of methods:
 *

        return "allintitle".equals(value) || "allinurl".equals(value);
    }

    /**
     * Escapes specific characters in a query string.
     * Replaces each specified character with its escaped version (prefixed with backslash).
     *
     * @param q the query string to escape
     * @param values the characters to escape
     * @return the escaped query string
     */

    private final SuccessorsFunction<Character> delegate;
    final Multiset<Character> requestedNodes = HashMultiset.create();

    RequestSavingGraph(SuccessorsFunction<Character> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    public Iterable<? extends Character> successors(Character node) {
      requestedNodes.add(node);

    private final SuccessorsFunction<Character> delegate;
    final Multiset<Character> requestedNodes = HashMultiset.create();

    RequestSavingGraph(SuccessorsFunction<Character> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    public Iterable<? extends Character> successors(Character node) {
      requestedNodes.add(node);

    }

    @Test
    @DisplayName("Should handle special characters in delimiter")
    void testJoinWithSpecialCharDelimiter() {
        String result = StringUtil.join("\\t", "tab", "separated", "values");
        assertEquals("tab\\tseparated\\tvalues", result);
    }

    @Test
    @DisplayName("Should handle Unicode characters in delimiter")
    void testJoinWithUnicodeDelimiter() {