test_class.pp

# Declare a class called test_class that takes a $content parameter.
class test_class(
    $content
) {
    file { "/tmp/f1.txt":
        content => $content
    }
}

# 'include' the test_class with content defined as "YOOHOOOO"
class { 'test_class': 
    content => "YOOHOOOO"
}