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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 _apply_over_vars_with_dim(func, self, dim=None, **kwargs):
    '''wrapper for datasets'''

    ds = type(self)(coords=self.coords, attrs=self.attrs)

    for name, var in self.data_vars.items():
        if dim in var.dims:
            ds[name] = func(var, dim=dim, **kwargs)
        else:
            ds[name] = var

    return ds