presto-main/src/main/java/io/prestosql/operator/scalar/annotations/ScalarFromAnnotationsParser.java/ScalarFromAnnotationsParser/parseFunctionDefinition
class ScalarFromAnnotationsParser:    public static List<SqlScalarFunction> parseFunctionDefinition(Class<?> clazz)
    {
        ImmutableList.Builder<SqlScalarFunction> builder = ImmutableList.builder();
        for (ScalarHeaderAndMethods scalar : findScalarsInFunctionDefinitionClass(clazz)) {
            builder.add(parseParametricScalar(scalar, FunctionsParserHelper.findConstructor(clazz)));
        }
        return builder.build();
    }