code: def _process_math(self, node, math_operator=None, function=None, **kwargs):
          
  
          with self._interpolation():
              if function:
                  self.output.write(function)
                  self.output.write('(')
  
              self._process_node(node.left, **kwargs)
              self.output.write(math_operator)
              self._process_node(node.right, **kwargs)
  
              if function:
                  self.output.write(')')
docs: Processes a math node e.g. `Div`, `Sub`, `Add`, `Mul` etc...
          If `function` is provided the expression is wrapped in a call to that function.