static MethodModel createContractHelper(ContractCreationTrait trait,
ContractAnnotationModel annotation) {
ContractKind kind = getContractKind(annotation);
MethodModel method = createBlankContractHelper(kind, annotation, null);
TypeName returnType =
new TypeName(kind.getVariance() == ContractVariance.CONTRAVARIANT
? trait.getExceptionName()
: "void");
method.setReturnType(returnType);
if (kind.getVariance() == ContractVariance.CONTRAVARIANT) {