delegate.assertOutputContains(expectedOutput);
        return this;
    }

    @Override
    public ExecutionResult assertContentContains(String content, String expectedOutput, String label) {
        delegate.assertContentContains(content, expectedOutput, label);
        return this;
    }

    @Override
    public ExecutionResult assertNotOutput(String expectedOutput) {

        // When
        assertSucceeds()

        // Then, assert content from both project's metadata is in final metadata
        upgradedProperties.assertContentContains("org.gradle.api.Task")
        upgradedProperties.assertContentContains("org.gradle.api.plugins.quality.Checkstyle")

        // Given, change only some classes but not metadata

        return this;
    }

    @Override
    public ExecutionResult assertHasPostBuildOutput(String expectedOutput) {
        return assertContentContains(postBuild.withNormalizedEol(), expectedOutput, "Post-build output");
    }

    @Override
    public ExecutionResult assertNotPostBuildOutput(String expectedOutput) {

     * @param expectedOutput The expected log message, with line endings normalized to a newline character.
     * @param label The label to use when printing a failure
     */
    ExecutionResult assertContentContains(String content, String expectedOutput, String label);

    /**
     * Asserts that this result does not include the given log message anywhere in the build output.
     *

            outputResult.assertOutputContains(expectedOutput);
            return this;
        }

        @Override
        public ExecutionResult assertContentContains(String content, String expectedOutput, String label) {
            outputResult.assertContentContains(content, expectedOutput, label);
            return null;
        }

        @Override