function handleArray(val) {
  const _this = this;
  if (!Array.isArray(val)) {
    return [this.cast(val)];
  }
  return val.map(function(m) {
    return _this.cast(m);
  });
}
Casts to number

@param {Object} value value to cast
@param {Document} doc document that triggers the casting
@param {Boolean} init
@api private