What are reasonable steps to ascertain the age of the person?

In respect of the offence of child internet luring (s. 172.1(1)(c)), s. 172.1(4) of the Code provided in material part as follows:

It is not a defence to a charge [of internet luring under s. 172.1(1)(c)] that the accused believed that the person ... was at least ... fourteen years of age ... unless the accused took reasonable steps to ascertain the age of the person.  

What does that mean? Today's decision in R. v. Dragos, 2012 ONCA 538 holds:

[35]       In my view, s. 172.1(4) requires an accused who claims mistake of age to have exercised a degree of care in ascertaining a complainant's age that a reasonable person in the circumstances would have exercised.  I say this for the following reasons.