public async Task AnalyzeEmptySolutionAsync()
        {
            // Given
            var analyzer = new FooAnalyzer();
            var project  = new InMemoryProject();
            var mocked   = new MockedAnalyzer <FooAnalyzer>(analyzer, project);

            // When
            var diagnostics = await mocked.AnalyzeAsync();

            // Then
            Assert.NotNull(diagnostics);
            Assert.Empty(diagnostics);
        }
        public async Task AnalyzeAsync()
        {
            // Given
            var analyzer = new FooAnalyzer();
            var project  = new InMemoryProject();
            var mocked   = new MockedAnalyzer <FooAnalyzer>(analyzer, project);

            // When
            mocked.AddCode("public class Foo { }");
            var diagnostics = await mocked.AnalyzeAsync();

            // Then
            Assert.NotNull(diagnostics);
            Assert.Single(diagnostics);
        }