/** @since Available in iOS 4.0 and later. */
 public CVImageBufferTransferFunction getTransferFunction() {
   if (has(CVImageBufferAttribute.TransferFunction)) {
     CFString val = get(CVImageBufferAttribute.TransferFunction, CFString.class);
     return CVImageBufferTransferFunction.valueOf(val);
   }
   return null;
 }
 /** @since Available in iOS 4.0 and later. */
 public CVImageBufferAttributes setTransferFunction(
     CVImageBufferTransferFunction transferFunction) {
   set(CVImageBufferAttribute.TransferFunction, transferFunction.value());
   return this;
 }