@BeforeExperiment
  protected void setUp() {
    BitSet bitSet = new BitSet();
    for (int i = 0; i < OLD_WHITESPACE_TABLE.length(); i++) {
      bitSet.set(OLD_WHITESPACE_TABLE.charAt(i));
    }
    bitSet.clear(0);
    bitSet.clear(1);
    matcher = useNew ? CharMatcher.whitespace() : OLD_WHITESPACE;
    teststring = newTestString(new Random(1), bitSet, percentMatching);
  }

  @Benchmark

 * to keep track of which items are filtered out of the source list.
 */
public class ImmutableFilteredList<T> extends AbstractList<T> {

    private final List<T> source;
    private final BitSet filter;

    private ImmutableFilteredList(List<T> source, BitSet filter) {
        this.source = source;
        this.filter = filter;
    }

    /**
     * Creates an {@code ImmutableFilteredList} which contains all the elements of {@code source}.

package main

const b26 uint64 = 0x022fdd63cc95386d

var bitPos [64]int

func init() {
	for p := uint(0); p < 64; p++ {
		bitPos[b26<<p>>58] = int(p)
	}
}

func MinPos(w uint64) int {
	if w == 0 {
		panic("bit: MinPos(0) undefined")
	}
	return bitPos[((w&-w)*b26)>>58]
}

func main() {
	const one = uint64(1)
	for i := 0; i < 64; i++ {

            // Because they are EXTRA attributes, we consider that a
            // candidate which does NOT provide this value is a better match
            int candidateCount = candidateAttributeSets.length;
            BitSet any = new BitSet(candidateCount);
            for (int c = 0; c < candidateCount; c++) {
                ImmutableAttributes candidateAttributeSet = candidateAttributeSets[c];

        table = (BitSet) table.clone();
        // If only we could actually call BitSet.trimToSize() ourselves...
      }
      this.table = table;
    }

    @Override
    public boolean matches(char c) {
      return table.get(c);
    }

    @Override
    void setBits(BitSet bitSet) {
      bitSet.or(table);
    }
  }

  // Static constant implementation classes

package com.google.common.base;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.CharMatcher.NamedFastMatcher;
import java.util.BitSet;

/**
 * An immutable version of CharMatcher for smallish sets of characters that uses a hash table with
 * linear probing to check for matches.
 *
 * @author Christopher Swenson
 */

        table = (BitSet) table.clone();
        // If only we could actually call BitSet.trimToSize() ourselves...
      }
      this.table = table;
    }

    @Override
    public boolean matches(char c) {
      return table.get(c);
    }

    @Override
    void setBits(BitSet bitSet) {
      bitSet.or(table);
    }
  }

  // Static constant implementation classes

package com.google.common.base;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.CharMatcher.NamedFastMatcher;
import java.util.BitSet;

/**
 * An immutable version of CharMatcher for smallish sets of characters that uses a hash table with
 * linear probing to check for matches.
 *
 * @author Christopher Swenson
 */

   *
   * <p><b>Note:</b> consider representing the array as a {@link java.util.BitSet} instead,
   * replacing {@code Booleans.contains(array, true)} with {@code !bitSet.isEmpty()} and {@code
   * Booleans.contains(array, false)} with {@code bitSet.nextClearBit(0) == sizeOfBitSet}.
   *
   * @param array an array of {@code boolean} values, possibly empty

   *
   * <p><b>Note:</b> consider representing the array as a {@link java.util.BitSet} instead,
   * replacing {@code Booleans.contains(array, true)} with {@code !bitSet.isEmpty()} and {@code
   * Booleans.contains(array, false)} with {@code bitSet.nextClearBit(0) == sizeOfBitSet}.
   *
   * @param array an array of {@code boolean} values, possibly empty