LambdaRestrictionStrategy not triggering for Lambda scripts

Traversals that use Lambda as described here:

http://tinkerpop.apache.org/docs/current/reference/#_the_lambda_solution

for example are not triggering the LambdaRestrictionStrategy. The problem is with the rule for the trigger itself which expects that the word "lambda" be in toString() of the step being evaluated. Currently steps that use Lambda don't produce that in their toString() - they simply return the lambda script. There are multiple fixes to this, but I think the easiest might be to just change the Lambda.toString() to include the word "lambda" and then it all just works.