* @throws ClassCastException if the parameters are not <i>mutually comparable</i> under this
   *     ordering.
   * @since 11.0
   */
  @ParametricNullness
  public <E extends T> E min(Iterator<E> iterator) {
    // let this throw NoSuchElementException as necessary
    E minSoFar = iterator.next();

    while (iterator.hasNext()) {
      minSoFar = this.<E>min(minSoFar, iterator.next());
    }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testIteratorRemove_unsupported() {
    Iterator<E> iterator = collection.iterator();
    iterator.next();
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
    expectUnchanged();
    assertTrue(collection.contains(e0()));
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)

    }
  }

  /**
   * Verifies that an Iterator is unmodifiable.
   *
   * <p>This test only works with iterators that iterate over a finite set.
   */
  public static void assertIteratorIsUnmodifiable(Iterator<?> iterator) {
    while (iterator.hasNext()) {
      iterator.next();
      try {
        iterator.remove();
        fail("Remove on unmodifiable iterator succeeded");

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.DoNotMock;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An iterator that supports a one-element lookahead while iterating.
 *
 * <p>See the Guava User Guide article on <a href=

 */
package org.codelibs.core.lang;

import static org.codelibs.core.misc.AssertionUtil.assertArgumentNotNull;

import java.util.Iterator;
import java.util.NoSuchElementException;

import org.codelibs.core.exception.ClUnsupportedOperationException;

/**
 * クラスローダの階層を親クラスローダに向かって反復する{@link Iterator}です。
 * <p>
 * 次のように使います．
 * </p>
 *
 * <pre>
 * import static org.codelibs.core.lang.ClassLoaderIterator.*;
 *

        assertEquals(pom0Basedir, project1.getParent().getBasedir());
        Set set = project1.getArtifacts();
        assertNotNull(set, "No artifacts");
        assertTrue(set.size() > 0, "No Artifacts");
        Iterator iter = set.iterator();
        assertTrue(set.size() == 4, "Set size should be 4, is " + set.size());

        while (iter.hasNext()) {
            Artifact artifact = (Artifact) iter.next();

  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  public void testKeySetIteratorRemove() {
    int key0Count = multimap().get(k0()).size();
    Iterator<K> keyItr = multimap().keySet().iterator();
    while (keyItr.hasNext()) {
      if (keyItr.next().equals(k0())) {
        keyItr.remove();
      }
    }
    assertEquals(getNumElements() - key0Count, multimap().size());

  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testKeySetIteratorRemove() {
    int initialSize = getNumElements();
    Iterator<K> iterator = getMap().keySet().iterator();
    iterator.next();
    iterator.remove();
    assertEquals(initialSize - 1, getMap().size());
    assertEquals(initialSize - 1, getMap().inverse().size());
  }

    private final Deque<Iterator<T>> stack;

    PreOrderIterator(T root) {
      this.stack = new ArrayDeque<>();
      stack.addLast(singletonIterator(checkNotNull(root)));
    }

    @Override
    public boolean hasNext() {
      return !stack.isEmpty();
    }

    @Override
    public T next() {
      Iterator<T> itr = stack.getLast(); // throws NSEE if empty

    FluentIterable<Integer> cycle = fluent(1, 2).cycle();
    Iterator<Integer> iterator = cycle.iterator();
    iterator.next();
    iterator.remove();
    iterator.next();
    iterator.remove();
    assertFalse(iterator.hasNext());
    assertFalse(cycle.iterator().hasNext());
  }

  public void testAppend() {
    FluentIterable<Integer> result =