@Test
  void formParamParseIntoFormParams() throws Exception {

    MethodMetadata md =
        parseAndValidateMetadata(
            FormParams.class, "loginNoBodyTemplate", String.class, String.class, String.class);

    assertThat(md.formParams()).containsExactly("customer_name", "user_name", "password");

    assertThat(md.indexToName())
        .containsExactly(
            entry(0, asList("customer_name")),
            entry(1, asList("user_name")),
            entry(2, asList("password")));
  }
Tests interfaces defined per {@link Contract.Default} are interpreted into expected {@link feign
.RequestTemplate template} instances.
core/src/test/java/feign/DefaultContractTest.java