code: def _CaptureExpression(self, frame, expression):
      
      rc, value = _EvaluateExpression(frame, expression)
      if not rc:
        return {'name': expression, 'status': value}
  
      return self.CaptureNamedVariable(expression, value, 0,
                                       self.expression_capture_limits)
docs: Evalutes the expression and captures it into a Variable object.
  
      Args:
        frame: evaluation context.
        expression: watched expression to compile and evaluate.
  
      Returns:
        Variable object (which will have error status if the expression fails
        to evaluate).