anchor.diff:      InferenceContext.setType(left, _typeProvider.boolType);
       InferenceContext.setType(right, _typeProvider.boolType);
   
  -    // TODO(scheglov) Do we need these checks for null?
  -    left?.accept(_resolver);
  +    left.accept(_resolver);
       left = node.leftOperand;
   
       if (_flowAnalysis != null) {
  
positive.code:   }
  
    void _resolveUserDefinable(BinaryExpressionImpl node) {
      Expression left = node.leftOperand;
      Expression right = node.rightOperand;
  
      // TODO(scheglov) Do we need these checks for null?
      left?.accept(_resolver);
  
      var operator = node.operator;
      _resolveUserDefinableElement(node, operator.lexeme);
  
negative.code:       InferenceContext.setType(right, rightParam.type);
      }
  
      right.accept(_resolver);
  
      _resolveUserDefinableType(node);
    }
  