*
 * This class tracks header values line-by-line. A field with multiple comma- separated values on
 * the same line will be treated as a field with a single value by this class. It is the caller's
 * responsibility to detect and split on commas if their field permits multiple values. This
 * simplifies use of single-valued fields whose values routinely contain commas, such as cookies or
 * dates.
 *

    depends on JUnit, though it continues to work with all testing frameworks.
 *  Fix: `FormEncodingBuilder` is now consistent with browsers in which
    characters it escapes. Previously we weren’t percent-encoding commas,
    parens, and other characters.
 *  Fix: Relax `FormEncodingBuilder` to support building empty forms.
 *  Fix: Timeouts throw `SocketTimeoutException`, not `InterruptedIOException`.