presto-main/src/main/java/io/prestosql/operator/scalar/annotations/ParametricScalarImplementation.java/Parser/getSignature
class Parser:        public Signature getSignature()
        {
            return new Signature(
                    functionName,
                    createTypeVariableConstraints(typeParameters, dependencies),
                    longVariableConstraints,
                    returnType,
                    argumentTypes,
                    false);
        }