code: def addVariant(self,variant):
          '''Appends one Variant to variants
  
          '''
          if isinstance(variant, Variant):
              self.variants.append(variant)
          else:
              raise (VariantError,
                     'variant Type should be Variant, not %s' % type(variant)f addVariant(self,variant):
          '''Appends one Variant to variants
  
          '''
          if isinstance(variant, Variant):
              self.variants.append(variant)
          else:
              raise (VariantError,
                     'variant Type should be Variant, not %s' % type(variant))
docs: Appends one Variant to variants