return new SingletonImmutableSet<>(e1);
  }

  /*
   * TODO: b/315526394 - Skip the Builder entirely for the of(...) methods, since we don't need to
   * worry that we might trigger the fallback to the JDK-backed implementation? (The varargs one
   * _could_, so we could keep it as it is. Or we could convince ourselves that hash flooding is
   * unlikely in practice there, too.)
   */

  /**

      // checkNotNull for GWT (do not optimize)
      array[i] = ((Number) checkNotNull(boxedArray[i])).intValue();
    }
    return array;
  }

  /**
   * Returns a fixed-size list backed by the specified array, similar to {@link
   * Arrays#asList(Object[])}. The list supports {@link List#set(int, Object)}, but any attempt to
   * set a value to {@code null} will result in a {@link NullPointerException}.
   *

  }

  /*
   * Tests that we workaround GWT bug #3621 (or that it is already fixed).
   *
   * A call to of() with a parameter that is not a plain Object[] (here,
   * Interface[]) creates a RegularImmutableSortedSet backed by an array of that
   * type. Later, RegularImmutableSortedSet.toArray() calls System.arraycopy()
   * to copy from that array to the destination array. This would be fine, but

      // checkNotNull for GWT (do not optimize)
      array[i] = ((Number) checkNotNull(boxedArray[i])).longValue();
    }
    return array;
  }

  /**
   * Returns a fixed-size list backed by the specified array, similar to {@link
   * Arrays#asList(Object[])}. The list supports {@link List#set(int, Object)}, but any attempt to
   * set a value to {@code null} will result in a {@link NullPointerException}.
   *

necessary.  Here is a sample; alter the names:

  Yoyodyne, Inc., hereby disclaims all copyright interest in the
  library `Frob' (a library for tweaking knobs) written by James Random
  Hacker.

  {signature of Ty Coon}, 1 April 1990
  Ty Coon, President of Vice

  }

  /*
   * Tests that we workaround GWT bug #3621 (or that it is already fixed).
   *
   * A call to of() with a parameter that is not a plain Object[] (here,
   * Interface[]) creates a RegularImmutableSortedSet backed by an array of that
   * type. Later, RegularImmutableSortedSet.toArray() calls System.arraycopy()
   * to copy from that array to the destination array. This would be fine, but

import java.util.ArrayList;
import java.util.Collection;

import org.codelibs.fess.opensearch.config.allcommon.EsAbstractConditionQuery;
import org.codelibs.fess.opensearch.config.cbean.cq.BadWordCQ;
import org.dbflute.cbean.ckey.ConditionKey;
import org.opensearch.index.query.BoolQueryBuilder;
import org.opensearch.index.query.CommonTermsQueryBuilder;
import org.opensearch.index.query.ExistsQueryBuilder;
import org.opensearch.index.query.IdsQueryBuilder;

import java.util.Collection;

import org.codelibs.fess.opensearch.config.allcommon.EsAbstractConditionQuery;
import org.codelibs.fess.opensearch.config.cbean.cq.BoostDocumentRuleCQ;
import org.dbflute.cbean.ckey.ConditionKey;
import org.opensearch.index.query.BoolQueryBuilder;
import org.opensearch.index.query.CommonTermsQueryBuilder;
import org.opensearch.index.query.ExistsQueryBuilder;
import org.opensearch.index.query.IdsQueryBuilder;

import java.util.ArrayList;
import java.util.Collection;

import org.codelibs.fess.opensearch.config.allcommon.EsAbstractConditionQuery;
import org.codelibs.fess.opensearch.config.cbean.cq.RequestHeaderCQ;
import org.dbflute.cbean.ckey.ConditionKey;
import org.opensearch.index.query.BoolQueryBuilder;
import org.opensearch.index.query.CommonTermsQueryBuilder;
import org.opensearch.index.query.ExistsQueryBuilder;
import org.opensearch.index.query.IdsQueryBuilder;

 *     Ordering.natural()
 *         .nullsFirst()
 *         .onResultOf(getBarFunction)
 *         .nullsLast();
 * }
 *
 * Note that each chaining method returns a new ordering instance which is backed by the previous
 * instance, but has the chance to act on values <i>before</i> handing off to that backing instance.
 * As a result, it usually helps to read chained ordering expressions <i>backwards</i>. For example,