presto-main/src/main/java/io/prestosql/operator/annotations/CastImplementationDependency.java/CastImplementationDependency/CastImplementationDependency
class CastImplementationDependency:    public CastImplementationDependency(TypeSignature fromType, TypeSignature toType, Optional<InvocationConvention> invocationConvention)
    {
        super(invocationConvention);
        this.fromType = requireNonNull(fromType, "fromType is null");
        this.toType = requireNonNull(toType, "toType is null");
    }