':type graph: DependencyGraph
:param graph: A dependency graph whose set of edges need to be
scored.
:rtype: A three-dimensional list of numbers.
:return: The score is returned in a multidimensional(3) list, such
that the outer-dimension refers to the head, and the
inner-dimension refers to the dependencies.  For instance,
scores[0][1] would reference the list of scores corresponding to
arcs from node 0 to node 1.  The node\'s \'address\' field can be used
to determine its number identification.
For further illustration, a score list corresponding to Fig.2 of
Keith Hall\'s \'K-best Spanning Tree Parsing\' paper:
scores = [[[], [5],  [1],  [1]],
[[], [],   [11], [4]],
[[], [10], [],   [5]],
[[], [8],  [8],  []]]
When used in conjunction with a MaxEntClassifier, each score would
correspond to the confidence of a particular edge being classified
with the positive training examples.'

def score(self, graph):

    raise NotImplementedError()
