container/src/main/java/com/streamsets/datacollector/record/HeaderImpl.java
public Map<String, Object> setUserAttributes(Map<String, Object> newAttributes) {
    // ImmutableMap can't have null values and our map could have, so use unmodifiable map
    Map<String, Object> old = Collections.unmodifiableMap(getUserAttributes());

    //Set current map to just the Reserved System Attributes
    map = getSystemAttributes();
    // Add and validate each of the new user attributes
    newAttributes.forEach((k,v) -> setAttribute(k, v.toString()));
    return old;
  }
public Map<String, Object> setUserAttributes(Map<String, Object> newAttributes) {
    // ImmutableMap can't have null values and our map could have, so use unmodifiable map
    Map<String, Object> old = Collections.unmodifiableMap(getUserAttributes());

    //Set current map to just the Reserved System Attributes
    map = getSystemAttributes();
    // Add and validate each of the new user attributes
    newAttributes.forEach((k,v) -> setAttribute(k, v.toString()));
    return old;
  }
To be removed