message: Use ColKey::is_collection()
diff: @@ -6,7 +6,7 @@ CollectionBase::CollectionBase(const Obj& owner, ColKey col_key)
  : m_obj(owner)
  , m_col_key(col_key)
  {
  - if (!((col_key.is_list() || col_key.is_dictionary() || col_key.is_set()))) {
  + if (!col_key.is_collection()) {
  throw LogicError(LogicError::collection_type_mismatch);
  }
  m_nullable = col_key.is_nullable();
  