*
   * @param element the element to prepend to the front of {@code array}
   * @param array the array of elements to append
   * @return an array whose size is one larger than {@code array}, with {@code element} occupying
   *     the first position, and the elements of {@code array} occupying the remaining elements.
   */

    // The choice of the size() method to call here is arbitrary.  We assume that if any of the Set
    // methods executes the validation check, they all will, and thus we only need to test one of
    // them to ensure that the validation check happens and has the expected behavior.
    assertNodeRemovedFromGraphErrorMessage(
        assertThrows(IllegalStateException.class, n1AdjacentNodes::size));

                    return (int) misses.incrementAndGet();
                  }
                });

    // To start, fill up the cache.
    // Each miss both increments the counter and causes the map to grow by one,
    // so until evictions begin, the size of the map is the greatest return
    // value seen so far
    while (cache.getUnchecked(nextRandomKey()) < maximumSize) {}

    requests.set(0);
    misses.set(0);
  }

## Define `Form` parameters { #define-form-parameters }

Create form parameters the same way you would for `Body` or `Query`:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[9] *}

For example, in one of the ways the OAuth2 specification can be used (called "password flow") it is required to send a `username` and `password` as form fields.

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

    this.readable = checkNotNull(readable);
    this.reader = (readable instanceof Reader) ? (Reader) readable : null;
  }

  /**
   * Reads a line of text. A line is considered to be terminated by any one of a line feed ({@code
   * '\n'}), a carriage return ({@code '\r'}), or a carriage return followed immediately by a
   * linefeed ({@code "\r\n"}).
   *

  /** Lock used whenever accessing the state variables (runningTasks, shutdown) of the executor */
  private final Object lock = new Object();

  /*
   * Conceptually, these two variables describe the executor being in
   * one of three states:
   *   - Active: shutdown == false
   *   - Shutdown: runningTasks > 0 and shutdown == true
   *   - Terminated: runningTasks == 0 and shutdown == true
   */
  @GuardedBy("lock")

    CharSource reader =
        new CharSource() {
          @Override
          public Reader openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }
            return new FilterReader(source.openStream()) {
              @Override
              public void close() throws IOException {
                super.close();