code: public RiakUserMetadata put(Map<String, String> metaMap)
      {
          for (Map.Entry<String, String> e : metaMap.entrySet())
          {
              BinaryValue wrappedKey = BinaryValue.unsafeCreate(e.getKey().getBytes());
              BinaryValue wrappedValue = BinaryValue.unsafeCreate(e.getValue().getBytes());
              meta.put(wrappedKey, wrappedValue);
          }
          return this;
      }
docs: TODO: deal with charset. Should add to annotation