Double Barrel names

Should the second part of a Double Barreled name be in lower case 

For Example

MR CHRISTOPHER WILLIAM CHESHIRE-GOWER is Returned as

{
  title: 'Mr',
  first: 'Christopher',
  middle: 'William',
  last: 'Cheshire-gower',
  nick: '',
  suffix: '',
  error: []
}

Should last not be 'Cheshire-Gower' as it is normally an amalgamation of two Surnames?

Many Thanks

Bill

