def is_homozygous(self):
if self.FORMAT is None:<EOL><INDENT>return False<EOL><DEDENT>else:<EOL><INDENT>genotypes = set(self.FORMAT.get('<STR_LIT>', '<STR_LIT>').split('<STR_LIT:/>'))<EOL>return '<STR_LIT:.>' not in genotypes and len(genotypes) == <NUM_LIT:1><EOL><DEDENT>
Returns true iff this variant has a GT field and is homozygous, which here
        means that the genotype is n/n (where n can be any number).