static Converter getBestConverter() {
      try {
        Class<?> theClass = Class.forName(UNSAFE_CONVERTER_NAME);

        // yes, UnsafeComparer does implement Comparer<byte[]>
        @SuppressWarnings("unchecked")
        Converter converter = (Converter) theClass.getConstructor().newInstance();
        return converter;
      } catch (Throwable t) { // ensure we really catch *everything*
        return PureJavaConverter.INSTANCE;
      }
    }
Returns the Unsafe-using Converter, or falls back to the pure-Java implementation if unable
to do so.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/Bytes.java