Can Groovy classes be used as FitNesse fixtures

I am learning the FitNesse framework and wondering if fixture code can be written in Groovy. So I made a copy of an example Decision Table, renamed the original class as ShouldIBuyMilkJava and created a Groovy class with same functionality. So my setup is like this:

wiki test page (table rows omitted for brevity):

|should I buy milk Java                                         |
|cash in wallet|credit card|pints of milk remaining|go to store?|
|0             |no         |0                      |no          |
|10            |no         |0                      |yes         |

|should I buy milk Groovy                                       |
|cash in wallet|credit card|pints of milk remaining|go to store?|
|0             |no         |0                      |no          |
|10            |no         |0                      |yes         |

ShouldIBuyMilkJava.java:

Same as here, except that the class is renamed to ShouldIBuyMilkJava

ShouldIBuyMilkGroovy.groovy:

class ShouldIBuyMilkGroovy {
    def dollars
    def pints
    boolean creditCard

    ShouldIBuyMilkGroovy() {

    }

    // the rest is omitted for brevity

Both classes are compiled successfully and are located in a folder that is imported as classpath in the test page. The first test passes successfully, but for the second I get an exception Could not invoke constructor for ShouldIBuyMilkGroovy[0].

I've tried removing an empty no-arg constructor from Groovy class - same result.

How can I make Groovy classes work as FitNesse fixtures?

So, the fix is simple - I had to include !path directive pointing at groovy library into FitNesse root page, not into the test page.