I'm writing Unit tests for some of my code, and I'm running into some problems..

I'll make a basic scenario --

class Alpha extends page{

static $belongs_many_many = array('Betas' => 'Beta');
}

class Beta extends page{

static $many_many = array('Alphas' => 'Alpha');
}

Now in my yml file I have :

Alpha:
a1:
Title: Alpha 1

Beta:
b1:
Title: Beta 1
Alphas: =>Alpha.a1

When I try an run one of my tests I get:
'Undefined index: Alpha'
PHPUnit_Util_ErrorHandler::handleError( 8, Undefined index: Alpha, ...path..., 246, Array)
YamlFixture->parseFixtureVal(=>Alpha.a1)
...

There really aren't many examples of dealing with many_many relations in SS's PHPUnit testing, so I'm clearly doing something wrong, but none of my tests have got me a working result :/

Thanks, that helped me try a few things that solved the problem..

The issue seems to be the order of elements in the YML file..

Basically, and I guess it wasn't reflected in my sample code, I was defining b1, and it's relation to Alphas a1 before I had defined a1.