code: public static void setSpecificInputContext(Configuration conf, String inputName, int inputId) {
      for (Map.Entry<String, String> entries : conf) {
        String confKey = entries.getKey();
        String confValue = entries.getValue();
        if (confKey.startsWith(MI_PREFIX + inputName + "." + inputId + CONF)) {
          // Specific context key, value found
          String contextKey = confKey.substring((MI_PREFIX + inputName + "." + inputId + CONF + ".").length(), confKey
              .length());
          conf.set(contextKey, confValue);
        }
      }
    }
docs: Iterates over the Configuration and sets the specific context found for the
  input in the Job instance. Package-access so it can be unit tested. The
  specific context is configured in method this.
  {@link #addInputContext(Job, String, String, String)}