code: def set_dimensions(self, variables, unlimited_dims=None):
          
          if unlimited_dims is None:
              unlimited_dims = set()
  
          existing_dims = self.get_dimensions()
  
          dims = OrderedDict()
          for v in unlimited_dims:  # put unlimited_dims first
              dims[v] = None
          for v in variables.values():
              dims.update(dict(zip(v.dims, v.shape)))
  
          for dim, length in dims.items():
              if dim in existing_dims and length != existing_dims[dim]:
                  raise ValueError(
                      "Unable to update size for existing dimension"
                      "%r (%d != %d)" % (dim, length, existing_dims[dim]))
              elif dim not in existing_dims:
                  is_unlimited = dim in unlimited_dims
                  self.set_dimension(dim, length, is_unlimited)
docs: This provides a centralized method to set the dimensions on the data
          store.
  
          Parameters
          ----------
          variables : dict-like
              Dictionary of key/value (variable name / xr.Variable) pairs
          unlimited_dims : list-like
              List of dimension names that should be treated as unlimited
              dimensions.