/**
     * Test rule matching with various ResponseData states
     */
    public void test_matchWithVariousResponseDataStates() {
        ConfigurableRule rule = new ConfigurableRule();
        rule.setRuleId("stateRule");
        rule.setResponseProcessor(new TestResponseProcessor("stateProcessor"));

        // Empty ResponseData
        ResponseData emptyData = new ResponseData();
        assertTrue(rule.match(emptyData));

 *
 * @since 3.0
 */
public interface LegacySupport {

    /**
     * Sets the currently active session. Some legacy components are basically stateful and their API is missing
     * parameters that would be required to delegate to a stateless component. Saving the session (in a thread-local

import java.net.InetAddress
import okhttp3.internal.interleave

/**
 * Implementation of HappyEyeballs Sorting Addresses.
 *
 * The current implementation does not address any of:
 *  - Async DNS split by IP class
 *  - Stateful handling of connectivity results
 *  - The prioritisation of addresses
 *
 * https://datatracker.ietf.org/doc/html/rfc8305#section-4
 */
internal fun reorderForHappyEyeballs(addresses: List<InetAddress>): List<InetAddress> {

	OpMuxServerMsg

	// OpUnblockSrvMux contains a message that a server mux is unblocked with one.
	// Only Stateful streams has flow control.
	OpUnblockSrvMux

	// OpUnblockClMux contains a message that a client mux is unblocked with one.
	// Only Stateful streams has flow control.
	OpUnblockClMux

	// OpAckMux acknowledges a mux was created.
	OpAckMux

Either side can use `rb.CloseWithError(err error)` to signal an error and close the ring buffer. 
Any reads or writes will return the error on next call.

import java.io.Writer;
import java.nio.charset.Charset;

/**
 * A destination to which bytes can be written, such as a file. Unlike an {@link OutputStream}, a
 * {@code ByteSink} is not an open, stateful stream that can be written to and closed. Instead, it
 * is an immutable <i>supplier</i> of {@code OutputStream} instances.
 *
 * <p>{@code ByteSink} provides two kinds of methods:
 *
 * <ul>

import java.io.Writer;
import java.nio.charset.Charset;

/**
 * A destination to which bytes can be written, such as a file. Unlike an {@link OutputStream}, a
 * {@code ByteSink} is not an open, stateful stream that can be written to and closed. Instead, it
 * is an immutable <i>supplier</i> of {@code OutputStream} instances.
 *
 * <p>{@code ByteSink} provides two kinds of methods:
 *
 * <ul>

/**
 * Resolves a POM from its coordinates. During the build process, the
 * {@link org.apache.maven.model.building.ModelBuilder} will add any relevant repositories to the model resolver. In
 * other words, the model resolver is stateful and should not be reused across multiple model building requests.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")
public interface ModelResolver {

      .build()
    assertThat(original.interceptors.size).isEqualTo(0)
    assertThat(original.networkInterceptors.size).isEqualTo(0)
  }

  /**
   * When copying the client, stateful things like the connection pool are shared across all
   * clients.
   */
  @Test fun cloneSharesStatefulInstances() {
    val client = clientTestRule.newClient()

    // Values should be non-null.

            return data != null ? new String(data) : null;
        }

        @Override
        public String getName() {
            return name;
        }
    }

    /**
     * Stateful transformer for testing state management
     */
    public static class StatefulTransformer implements Transformer {
        private final String name;
        private final List<String> processedUrls = new ArrayList<>();