liquibase-core/src/main/java/liquibase/util/StringClauses.java
public StringClauses prepend(String clause) {
        if (StringUtil.trimToNull(clause) == null) {
            return prepend(new Whitespace(clause));
        }
        return prepend(uniqueKey(clause), clause);
    }
public StringClauses prepend(String clause) {
        if (StringUtil.trimToNull(clause) == null) {
            return prepend(new Whitespace(clause));
        }
        return prepend(uniqueKey(clause), clause);
    }
Convenience method for {@link #prepend(String, String)} that uses the clause as the key.