code: def _construct_direct(cls, variables, coord_names, dims, attrs=None,
                            indexes=None, encoding=None, file_obj=None):
          
          obj = object.__new__(cls)
          obj._variables = variables
          obj._coord_names = coord_names
          obj._dims = dims
          obj._indexes = indexes
          obj._attrs = attrs
          obj._file_obj = file_obj
          obj._encoding = encoding
          obj._initialized = True
          return obj
docs: Shortcut around __init__ for internal use when we want to skip
          costly validation