Function<? super F, T> function, Supplier<F> supplier) {
    return new SupplierComposition<>(function, supplier);
  }

  private static class SupplierComposition<F extends @Nullable Object, T extends @Nullable Object>
      implements Supplier<T>, Serializable {
    final Function<? super F, T> function;
    final Supplier<F> supplier;

    SupplierComposition(Function<? super F, T> function, Supplier<F> supplier) {

   * {@code function} to the argument, then evaluating using {@code this}. That is, for any pair of
   * non-null objects {@code x} and {@code y}, {@code equivalence.onResultOf(function).equivalent(a,
   * b)} is true if and only if {@code equivalence.equivalent(function.apply(a), function.apply(b))}
   * is true.
   *
   * <p>For example:
   *
   * <pre>{@code

import java.io.Serializable;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Spliterator;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

   * {@code function} to the argument, then evaluating using {@code this}. That is, for any pair of
   * non-null objects {@code x} and {@code y}, {@code equivalence.onResultOf(function).equivalent(a,
   * b)} is true if and only if {@code equivalence.equivalent(function.apply(a), function.apply(b))}
   * is true.
   *
   * <p>For example:
   *
   * <pre>{@code

   *
   * @param g the second function to apply
   * @param f the first function to apply
   * @return the composition of {@code f} and {@code g}
   * @see <a href="//en.wikipedia.org/wiki/Function_composition">function composition</a>
   */
  public static <A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      Function<A, C> compose(Function<B, C> g, Function<A, ? extends B> f) {

   * Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *
   * @since 21.0
   */
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {

    }
  }

  private static String encode(String str) {
    return BaseEncoding.base64().encode(str.getBytes(Charsets.UTF_8));
  }

  private static final Function<String, String> DECODE_FUNCTION =
      new Function<String, String>() {
        @Override
        public String apply(String input) {
          return new String(BaseEncoding.base64().decode(input), Charsets.UTF_8);
        }
      };

   * bit(i) can alter output bit(j).
   */
  static void checkNoFunnels(HashFunction function) {
    Random rand = new Random(0);
    int keyBits = 32;
    int hashBits = function.bits();

    // output loop tests input bit
    for (int i = 0; i < keyBits; i++) {
      int same = 0x0; // bitset for output bits with same values

   */
  public final <T extends @Nullable Object> FluentIterable<T> transform(
      Function<? super E, T> function) {
    return from(Iterables.transform(getDelegate(), function));
  }

  /**
   * Applies {@code function} to each element of this fluent iterable and returns a fluent iterable
   * with the concatenated combination of results. {@code function} returns an Iterable of results.
   *

import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Function;
import com.google.common.base.Functions;
import com.google.common.base.Joiner;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.testing.IteratorFeature;