return emptySet(comparator());
    }
  }

  @Nullable E higher(E e) {
    checkNotNull(e);
    Iterator<E> iterator = tailSet(e).iterator();
    while (iterator.hasNext()) {
      E higher = iterator.next();
      if (comparator().compare(e, higher) < 0) {
        return higher;
      }
    }
    return null;
  }

  public @Nullable E ceiling(E e) {

/*
 * © 2025 CodeLibs, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

     * <li><code>[1.0,2.0]</code> Versions 1.0 to 2.0 (both included)</li>
     * <li><code>[1.5,)</code> Versions 1.5 and higher</li>
     * <li><code>(,1.0],[1.2,)</code> Versions up to 1.0 (included) and 1.2 or higher</li>
     * </ul>
     *
     * @param spec string representation of a version or version range
     * @return a new {@link VersionRange} object that represents the spec

/*
 * © 2025 CodeLibs, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.io;

 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.base;

 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.collect;

is widely used on most Java projects within Google, and widely used by many
other companies as well.



Guava comes in two flavors:

*   The JRE flavor requires JDK 1.8 or higher.
*   If you need support for Android, use
    [the Android flavor](https://github.com/google/guava/wiki/Android). You can
    find the Android Guava source in the [`android` directory].

/*
 * © 2025 CodeLibs, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

          assertEquals(unfiltered.floor(i), filtered.floor(i));
          assertEquals(unfiltered.ceiling(i), filtered.ceiling(i));
          assertEquals(unfiltered.higher(i), filtered.higher(i));
        }
      }
    }
  }

  private FilteredCollectionsTestUtil() {}