code: public static String applyPrefixSuffix(String uriSource, 
              Configuration conf) {
          if (uriSource == null) return null;
          String prefix = conf.get(OUTPUT_URI_PREFIX);
          String suffix = conf.get(OUTPUT_URI_SUFFIX);
          if (prefix == null && suffix == null) {
              return uriSource;
          }
          int len = uriSource.length() +
                  (prefix != null ? prefix.length() : 0) +
                  (suffix != null ? suffix.length() : 0);
          StringBuilder uriBuf = new StringBuilder(len);
          if (prefix != null) {
              uriBuf.append(prefix);
          }
          uriBuf.append(uriSource);
          if (suffix != null) {
              uriBuf.append(suffix);
          }
          return uriBuf.toString();
      }
docs: Apply URI prefix and suffix configuration option to a URI source string.
  
  @param uriSource
  @param conf
  @return result URI string