def grid(self, z_x_y):
        """ Return the UTFGrid content """
        # sources.py -> MapnikRenderer -> grid
        (z, x, y) = z_x_y
        content = self.reader.grid(z, x, y, self.grid_fields, self.grid_layer)
        return content
def grid ( self , z_x_y ) : ( z , x , y ) = z_x_y content = self . reader . grid ( z , x , y , self . grid_fields , self . grid_layer ) return content
Return the UTFGrid content