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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def is_triangular(self, var):
 """ Test if a variable is on a triangular grid This method first checks the `grid_type` attribute of the variable (if existent) whether it is equal to ``"unstructered"``, then it checks whether the bounds are not two-dimensional. Parameters var: xarray.Variable or xarray.DataArray The variable to check Returns ------- bool True, if the grid is triangular, else False"""

        warn("The 'is_triangular' method is depreceated and will be removed "
             "soon! Use the 'is_unstructured' method!", DeprecationWarning,
             stacklevel=1)
        return str(var.attrs.get('grid_type')) == 'unstructured' or \
            self._check_triangular_bounds(var)[0]