<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def is_unstructured(self, var):
 """ Test if a variable is on an unstructered grid Parameters %(CFDecoder.is_triangular.parameters)s Returns ------- %(CFDecoder.is_triangular.returns)s Notes ----- Currently this is the same as :meth:`is_triangular` method, but may change in the future to support hexagonal grids"""

        if str(var.attrs.get('grid_type')) == 'unstructured':
            return True
        xcoord = self.get_x(var)
        if xcoord is not None:
            bounds = self._get_coord_cell_node_coord(xcoord)
            if bounds is not None and bounds.shape[-1] > 2:
                return True