public void AddCustomHeader_AddAlreadyExistingCustomHeader_ReturnsFalse()
        {
            SimpleHttpClient.SimpleClientConfig model = Mockup.GetMockupConfigWithCustomHeader();
            var result = model.AddCustomHeader(Mockup.MockCustomHeaderKey, "value");

            Assert.IsFalse(result);
        }
        public void AddCustomHeader_AddCustomHeader_ReturnsTrue()
        {
            SimpleHttpClient.SimpleClientConfig model = Mockup.GetMockupConfig();
            var result = model.AddCustomHeader("key", "value");

            Assert.IsTrue(result);
        }