def score_variant(self, variant1, variant2):
if variant1 == variant2:<EOL><INDENT>return <NUM_LIT:0.0><EOL><DEDENT>else:<EOL><INDENT>return <NUM_LIT:1.0><EOL><DEDENT>
Returns a match score between *variant1* and *variant2*.

An exact match returns 0.0, otherwise 1.0.