default T since(final String version) {
        return add(DefaultJavadocTag.SINCE.setValue(version));
    }
Adds an {@link DefaultJavadocTag#SINCE}-tag with the specified value to
this javadoc.

@param version  version for the {@code since} tag
@return         a reference to this
common-parent/codegen/src/main/java/com/speedment/common/codegen/model/trait/HasJavadocTags.java