mergeSpec.eachEntry {ManifestMergeDetails details ->
            if (details.getBaseValue() != null && details.getMergeValue() == null) {
                details.exclude();
            }
        }

        expect:
        mergeSpec.merge(baseManifest, Mock(FileResolver)).sections.section == [key2: 'mergeValue2']
    }

    def mergeWithForeignManifest() {

    private String baseValue;
    private String mergeValue;
    private String value;
    private boolean excluded;

    public DefaultManifestMergeDetails(String section, String key, String baseValue, String mergeValue, String value) {
        this.section = section;
        this.key = key;
        this.baseValue = baseValue;
        this.mergeValue = mergeValue;
        this.value = value;
    }

    @Override

        for (Map.Entry<String, Object> baseEntry : baseAttributes.entrySet()) {
            Object mergeValue = mergeAttributes.get(baseEntry.getKey());
            mergeDetailsSet.add(getMergeDetails(section, baseEntry.getKey(), baseEntry.getValue(), mergeValue));
            mergeOnlyAttributes.remove(baseEntry.getKey());
        }

        from sharedManifest, 'src/config/basemanifest.txt'
        from(['src/config/javabasemanifest.txt', 'src/config/libbasemanifest.txt']) {
            eachEntry { details ->
                if (details.baseValue != details.mergeValue) {
                    details.value = baseValue
                }
                if (details.key == 'foo') {
                    details.exclude()
                }
            }
        }
    }
}

        from(listOf("src/config/javabasemanifest.txt", "src/config/libbasemanifest.txt")) {
            eachEntry(Action<ManifestMergeDetails> {
                if (baseValue != mergeValue) {
                    value = baseValue
                }
                if (key == "foo") {
                    exclude()
                }
            })
        }
    }
}
// end::merge[]