core/src/main/java/com/twitter/elephantbird/util/HadoopUtils.java
public static void setClassConf(Configuration  conf,
                                  String         configKey,
                                  Class<?>       clazz) {
    String existingClass = conf.get(configKey);
    String className = clazz.getName();

    if (existingClass != null && !existingClass.equals(className)) {
        throw new RuntimeException(
            "Already registered a different thriftClass for "
            + configKey
            + ". old: " + existingClass
            + " new: " + className);
    } else {
      conf.set(configKey, className);
    }
  }
public static void setClassConf(Configuration  conf,
                                  String         configKey,
                                  Class<?>       clazz) {
    String existingClass = conf.get(configKey);
    String className = clazz.getName();

    if (existingClass != null && !existingClass.equals(className)) {
        throw new RuntimeException(
            "Already registered a different thriftClass for "
            + configKey
            + ". old: " + existingClass
            + " new: " + className);
    } else {
      conf.set(configKey, className);
    }
  }
A helper to set configuration to class name.
Throws a RuntimeExcpetion if the
configuration is already set to a different class name.