export default function(usernames) {
  const normalisedNames = usernames.split(',').map((i) => i.trim().toLowerCase());
  const removedBlanks = normalisedNames.filter((i) => i.length > 0);
  const removedDuplicates = removedBlanks.filter((name, pos) => {
      return removedBlanks.indexOf(name) == pos;
  });

  return removedDuplicates;
}