public async Task ValidateAsync_WithEmptyHeader_ValidationSucessfullAsync()
        {
            // Arrange
            var testee = new NoInvalidCharactersInKeywordsValidator();
            var header = new HeaderBuilder()
                         .WithEmptyHeader()
                         .Build();

            // Act
            var result = await testee.ValidateAsync(header);

            // Assert
            result.ValidationSuccessful.Should().Be(true);
            result.ValidationFailureMessage.Should().BeNull();
        }
        public async Task ValidateAsync_WithValidCharacter_ValidacionSucessfulAsync(char invalidCharacter)
        {
            // Arrange
            var testee = new NoInvalidCharactersInKeywordsValidator();
            var header = new HeaderBuilder()
                         .WithHeaderEntry(
                key: $"{invalidCharacter}",
                value: null,
                comment: null)
                         .Build();

            // Act
            var result = await testee.ValidateAsync(header);

            // Assert
            result.ValidationSuccessful.Should().Be(true);
            result.ValidationFailureMessage.Should().BeNull();
        }
        public async Task ValidateAsync_WithInvalidCharacter_ValidacionFailsAsync(char invalidCharacter)
        {
            // Arrange
            var testee = new NoInvalidCharactersInKeywordsValidator();
            var header = new HeaderBuilder()
                         .WithHeaderEntry(
                key: $"{invalidCharacter}",
                value: null,
                comment: null)
                         .Build();

            // Act
            var result = await testee.ValidateAsync(header);

            // Assert
            result.ValidationSuccessful.Should().Be(false);
            result.ValidationFailureMessage.Should().Be($"The header key \"{invalidCharacter}\" contains not allowed characters!");
        }