code: public void setDataUsageFor(String activity, Map<String, Set<DataUsage>> dataUsage) throws CompatibilityException {
                  validateActivity(activity);
                  validateDataUsage(dataUsage);
                  activityDataUsage.put(activity, dataUsage);
          }
docs: Sets the data attributes used by the given activity together with
  their usage.<br>
  The given activity/attributes have to be known by the context, i.e.
  be contained in the activity/attribute list.
  
  @param activity Activity for which the attribute usage is set.
  @param dataUsage Data usage of input attributes.
  @throws ParameterException
  @throws CompatibilityException
  @throws IllegalArgumentException If the given activity/attributes are
  not known.
  @throws NullPointerException If the data usage set is
  <code>null</code>
  @see DataUsage
  @see #getActivities()
  @see #getAttributes()
  @see #setAttributes(Set)