forEachAccumulated = function(arr, cb, scope) {
  if (Array.isArray(arr)) {
    arr.forEach(cb, scope);
  } else if (arr) {
    cb.call(scope, arr);
  }
}
@param {array} an "accumulation" of items which is either an Array or
a single item. Useful when paired with the `accumulate` module. This is a
simple utility that allows us to reason about a collection of items, but
handling the case when there is exactly one item (and we do not need to
allocate an array).