*
   * @since 20.0 (varargs overload since 2.0)
   */
  public static void checkArgument(
      boolean expression, String errorMessageTemplate, char p1, char p2) {
    if (!expression) {
      throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
    }
  }

  /**

        }
    }

    @Override
    public String toString() {
        final int len = this.length / 2 - (this.zterm ? 1 : 0);
        final char[] ca = new char[len];
        for (int i = 0; i < len; i++) {
            ca[i] = (char) this.buffer[i];
        }
        return new String(ca, 0, len);
    }

        assertEquals(testStringTrue.length() + 1, unicodeStringTrue.buffer.length, "Buffer length should include zterm");
        for (int i = 0; i < testStringTrue.length(); i++) {
            assertEquals(testStringTrue.charAt(i), (char) unicodeStringTrue.buffer[i], "Character mismatch");
        }
        assertEquals(0, unicodeStringTrue.buffer[testStringTrue.length()], "Last character should be zero");

        // Test with a non-empty string and zterm = false

    /**
     * Detail/bullet point icon.
     */
    DETAIL('•', "-"),

    /**
     * Action/arrow icon.
     */
    ACTION('→', ">");

    private final char unicodeChar;
    private final String asciiFallback;

    ConsoleIcon(char unicodeChar, String asciiFallback) {
        this.unicodeChar = unicodeChar;
        this.asciiFallback = asciiFallback;
    }

    /**

    assertThat(expected).hasMessageThat().isEqualTo(msg);
  }

  public void testBadArguments_plusforspace() {
    // space can be a safe char if plusForSpace is false
    PercentEscaper unused = new PercentEscaper(" ", false);

    // space cannot be a safe char is plusForSpace is true
    String msg = "plusForSpace cannot be specified when space is a 'safe' character";
    IllegalArgumentException expected =

   */
  private static char[] growBuffer(char[] dest, int index, int size) {
    if (size < 0) { // overflow - should be OutOfMemoryError but GWT/j2cl don't support it
      throw new AssertionError("Cannot increase internal buffer any further");
    }
    char[] copy = new char[size];
    if (index > 0) {
      System.arraycopy(dest, 0, copy, 0, index);
    }

      chars.add(randomNonAlpha());
    }
    Collections.shuffle(chars, random);
    char[] array = Chars.toArray(chars);
    this.testString = new String(array);
  }

  private char randomAlpha() {
    return ALPHA.charAt(random.nextInt(ALPHA.length()));
  }

  private char randomNonAlpha() {
    return NONALPHA.charAt(random.nextInt(NONALPHA.length()));
  }

  @Benchmark

import java.io.FilterWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import org.jspecify.annotations.NullUnmarked;

/**
 * A char sink for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class TestCharSink extends CharSink implements TestStreamSupplier {

  private final TestByteSink byteSink;

import java.io.FilterWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import org.jspecify.annotations.NullUnmarked;

/**
 * A char sink for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class TestCharSink extends CharSink implements TestStreamSupplier {

  private final TestByteSink byteSink;

  void tearDown() throws IOException;

  /** Factory for byte or char sources. */
  interface SourceFactory<S, T> extends SourceSinkFactory<S, T> {

    /** Creates a new source containing some or all of the given data. */
    S createSource(T data) throws IOException;
  }

  /** Factory for byte or char sinks. */
  interface SinkFactory<S, T> extends SourceSinkFactory<S, T> {