* PackageSanityTests. (The test would run on the JVM, too, if not for the suppression below, and
   * that would be a problem because it violates small-test rules. Note that we strip the
   * suppression externally, but it's OK because we don't enforce test-size rules there.)
   *
   * We'd just use PackageSanityTests directly, saving us from needing this separate type, but we're

   * PackageSanityTests. (The test would run on the JVM, too, if not for the suppression below, and
   * that would be a problem because it violates small-test rules. Note that we strip the
   * suppression externally, but it's OK because we don't enforce test-size rules there.)
   *
   * We'd just use PackageSanityTests directly, saving us from needing this separate type, but we're

   * with a CR+LF pair</a> on any non-file inputs before escaping them with this escaper.
   *
   * <p>When escaping a String, the following rules apply:
   *
   * <ul>
   *   <li>The alphanumeric characters "a" through "z", "A" through "Z" and "0" through "9" remain
   *       the same.
   *   <li>The special characters ".", "-", "*", and "_" remain the same.

    ArrayList<Throwable> temp = new ArrayList<>(Arrays.asList(exceptions));
    return create(temp);
  }

  /**
   * Given a collection of exceptions, returns a {@link RuntimeException}, with the following rules:
   *
   * <ul>
   *   <li>If {@code exceptions} has a single exception and that exception is a {@link
   *       RuntimeException}, return it

 * directly if required. While URI escapers impose specific semantics on which characters are
 * considered 'safe', this class has a minimal set of restrictions.
 *
 * <p>When escaping a String, the following rules apply:
 *
 * <ul>
 *   <li>All specified safe characters remain unchanged.
 *   <li>If {@code plusForSpace} was specified, the space character " " is converted into a plus
 *       sign {@code "+"}.

   * a "hole" in it so that set tests of {@code ContiguousSet} can suppress them with {@code
   * FeatureSpecificTestSuiteBuilder.suppressing()}.
   */
  /*
   * TODO(cpovirk): or we could make HOLES_FORBIDDEN a feature. Or we could declare that
   * implementations are permitted to throw IAE if a hole is requested, and we could update
   * test*Hole to permit IAE. (But might this ignore genuine bugs?) But see the TODO above

final class MathPreconditions {
  @CanIgnoreReturnValue
  static int checkPositive(String role, int x) {
    if (x <= 0) {
      throw new IllegalArgumentException(role + " (" + x + ") must be > 0");
    }
    return x;
  }

  @CanIgnoreReturnValue
  static long checkPositive(String role, long x) {
    if (x <= 0) {
      throw new IllegalArgumentException(role + " (" + x + ") must be > 0");
    }
    return x;
  }

   * a "hole" in it so that set tests of {@code ContiguousSet} can suppress them with {@code
   * FeatureSpecificTestSuiteBuilder.suppressing()}.
   */
  /*
   * TODO(cpovirk): or we could make HOLES_FORBIDDEN a feature. Or we could declare that
   * implementations are permitted to throw IAE if a hole is requested, and we could update
   * test*Hole to permit IAE. (But might this ignore genuine bugs?) But see the TODO above

    ArrayList<Throwable> temp = new ArrayList<>(Arrays.asList(exceptions));
    return create(temp);
  }

  /**
   * Given a collection of exceptions, returns a {@link RuntimeException}, with the following rules:
   *
   * <ul>
   *   <li>If {@code exceptions} has a single exception and that exception is a {@link
   *       RuntimeException}, return it