public @NonNull T next() {
      T result = valueOrNull;
      valueOrNull = null;
      // We put the common case first, even though it's unlikely to matter if the code is run much:
      // https://shipilev.net/jvm/anatomy-quarks/28-frequency-based-code-layout/
      if (result != null) {
        return result;
      }
      throw new NoSuchElementException();
    }
  }

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.net;

import com.google.common.annotations.GwtCompatible;

/**
 * Contains constant definitions for the HTTP header field names. See:
 *
 * <ul>
 *   <li><a href="http://www.ietf.org/rfc/rfc2109.txt">RFC 2109</a>