import java.io.Writer;
import java.util.Arrays;
import java.util.Objects;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A binary encoding scheme for reversibly translating between byte sequences and printable ASCII
 * strings. This class includes several constants for encoding schemes specified by <a
 * href="http://tools.ietf.org/html/rfc4648">RFC 4648</a>. For example, the expression:
 *

 *         .transformAsync((closer, transaction) -> transaction.queryClosingFuture("..."), executor)
 *         .transform((closer, result) -> result.get("userName"), directExecutor())
 *         .catching(DBException.class, e -> "no user", directExecutor())
 *         .finishToFuture();
 * }</pre>
 *
 * In this example, when the {@code userName} {@link Future} is done, the transaction and the query