code: public void addDataUsageForAll(Collection<String> activities, String attribute, DataUsage dataUsage) {
                  Validate.notNull(activities);
                  Validate.notEmpty(activities);
                  for (String activity : activities) {
                          addDataUsageFor(activity, attribute, dataUsage);
                  }
          }
docs: Adds a data attribute for all given activities together with its
  usage.<br>
  The given activities/attributes have to be known by the context, i.e.
  be contained in the activity/attribute list.
  
  @param activities Activities for which the attribute usage is set.
  @param attribute Attribute used by the given activities.
  @param dataUsage Usage of the data attribute by the given activities.
  @throws ParameterException
  @throws IllegalArgumentException IllegalArgumentException If the
  given activities/attributes are not known.
  @see #getActivities()
  @see #getAttributes()
  @see #setAttributes(Set)