Author email addresses were included in the doc strings for some (but not all)
stdlib functions. This commit removes them in the interest of consistency.
While developing Puppet Modules with class parameters, data from the
user should be validated as per the Style Guide. Puppet should fail
early and hard in the situation of invalid data being passed into the
module.
This function provides a more concise method to the alternative of using
if statements in the Puppet manifests.