core/src/main/java/com/twitter/elephantbird/util/ThriftUtils.java
public static <M> M getFieldValue(Object containingObject, String fieldName, Class<M> fieldClass) {
    return getFieldValue(containingObject.getClass(), containingObject, fieldName, fieldClass);
  }
public static <M> M getFieldValue(Object containingObject, String fieldName, Class<M> fieldClass) {
    return getFieldValue(containingObject.getClass(), containingObject, fieldName, fieldClass);
  }
Returns value of a fieldName in an object.