@Override
    public DataTableType dataTableType() {
        return dataTableType;
    }
@Test
    void target_type_must_class_type() throws NoSuchMethodException {
        Method method = JavaDataTableTypeDefinitionTest.class.getMethod("converts_datatable_to_optional_string",
            DataTable.class);
        JavaDataTableTypeDefinition definition = new JavaDataTableTypeDefinition(method, lookup, new String[0]);
        assertThat(definition.dataTableType().transform(dataTable.cells()),
            is(Optional.of("converts_datatable_to_optional_string")));

    }