code: def evaluate(self, *args, **kwargs):
      vl = self.get_child(0).evaluate(*args, **kwargs)
      vr = self.get_child(1).evaluate(*args, **kwargs)
  
      return Batch.combine_batches(vl, vr, self.etype)
  
imports: from evadb.expression.abstract_expression import AbstractExpression, ExpressionReturnType, ExpressionType
  from evadb.models.storage.batch import Batch
label_desc: Use image node_id 2 for calling the ArithmeticExpression obj's underlying member method code with example usage: obj.evaluate() and returns: Batch